diff --git a/lightrag_webui/src/api/lightrag.ts b/lightrag_webui/src/api/lightrag.ts
index 265126c7..a86519d4 100644
--- a/lightrag_webui/src/api/lightrag.ts
+++ b/lightrag_webui/src/api/lightrag.ts
@@ -99,6 +99,9 @@ export type QueryMode = 'naive' | 'local' | 'global' | 'hybrid' | 'mix' | 'bypas
 export type Message = {
   role: 'user' | 'assistant' | 'system'
   content: string
+  thinkingContent?: string
+  displayContent?: string
+  thinkingTime?: number
 }
 
 export type QueryRequest = {
diff --git a/lightrag_webui/src/components/retrieval/ChatMessage.tsx b/lightrag_webui/src/components/retrieval/ChatMessage.tsx
index 0314fd92..18b4fb25 100644
--- a/lightrag_webui/src/components/retrieval/ChatMessage.tsx
+++ b/lightrag_webui/src/components/retrieval/ChatMessage.tsx
@@ -15,12 +15,13 @@ import type { Element } from 'hast'
 import { Prism as SyntaxHighlighter } from 'react-syntax-highlighter'
 import { oneLight, oneDark } from 'react-syntax-highlighter/dist/cjs/styles/prism'
 
-import { LoaderIcon, CopyIcon } from 'lucide-react'
+import { LoaderIcon, CopyIcon, ChevronDownIcon } from 'lucide-react'
 import { useTranslation } from 'react-i18next'
 
 export type MessageWithError = Message & {
   id: string // Unique identifier for stable React keys
   isError?: boolean
+  isThinking?: boolean // Flag to indicate if the message is in a "thinking" state
   /**
    * Indicates if the mermaid diagram in this message has been rendered.
    * Used to persist the rendering state across updates and prevent flickering.
@@ -33,6 +34,16 @@ export const ChatMessage = ({ message }: { message: MessageWithError }) => { //
   const { t } = useTranslation()
   const { theme } = useTheme()
   const [katexPlugin, setKatexPlugin] = useState<any>(null)
+  const [isThinkingExpanded, setIsThinkingExpanded] = useState<boolean>(false)
+
+  // Directly use props passed from the parent.
+  const { thinkingContent, displayContent, thinkingTime, isThinking } = message
+
+  // The content to display is now non-ambiguous.
+  const finalThinkingContent = thinkingContent
+  // For user messages, displayContent will be undefined, so we fall back to content.
+  // For assistant messages, we prefer displayContent.
+  const finalDisplayContent = message.role === 'user' ? message.content : displayContent
 
   // Load KaTeX dynamically
   useEffect(() => {
@@ -59,6 +70,27 @@ export const ChatMessage = ({ message }: { message: MessageWithError }) => { //
     }
   }, [message, t]) // Added t to dependency array
 
+  const mainMarkdownComponents = useMemo(() => ({
+    code: (props: any) => (
+      <CodeHighlight
+        {...props}
+        renderAsDiagram={message.mermaidRendered ?? false}
+      />
+    ),
+    p: ({ children }: { children?: ReactNode }) => <p className="my-2">{children}</p>,
+    h1: ({ children }: { children?: ReactNode }) => <h1 className="text-xl font-bold mt-4 mb-2">{children}</h1>,
+    h2: ({ children }: { children?: ReactNode }) => <h2 className="text-lg font-bold mt-4 mb-2">{children}</h2>,
+    h3: ({ children }: { children?: ReactNode }) => <h3 className="text-base font-bold mt-3 mb-2">{children}</h3>,
+    h4: ({ children }: { children?: ReactNode }) => <h4 className="text-base font-semibold mt-3 mb-2">{children}</h4>,
+    ul: ({ children }: { children?: ReactNode }) => <ul className="list-disc pl-5 my-2">{children}</ul>,
+    ol: ({ children }: { children?: ReactNode }) => <ol className="list-decimal pl-5 my-2">{children}</ol>,
+    li: ({ children }: { children?: ReactNode }) => <li className="my-1">{children}</li>
+  }), [message.mermaidRendered]);
+
+  const thinkingMarkdownComponents = useMemo(() => ({
+    code: (props: any) => (<CodeHighlight {...props} renderAsDiagram={message.mermaidRendered ?? false} />)
+  }), [message.mermaidRendered]);
+
   return (
     <div
       className={`${
@@ -69,55 +101,76 @@ export const ChatMessage = ({ message }: { message: MessageWithError }) => { //
             : 'w-[95%] bg-muted'
       } rounded-lg px-4 py-2`}
     >
-      <div className="relative">
-        <ReactMarkdown
-          className="prose dark:prose-invert max-w-none text-sm break-words prose-headings:mt-4 prose-headings:mb-2 prose-p:my-2 prose-ul:my-2 prose-ol:my-2 prose-li:my-1 [&_.katex]:text-current [&_.katex-display]:my-4 [&_.katex-display]:overflow-x-auto"
-          remarkPlugins={[remarkGfm, remarkMath]}
-          rehypePlugins={[
-            ...(katexPlugin ? [[
-              katexPlugin,
-              {
-                errorColor: theme === 'dark' ? '#ef4444' : '#dc2626',
-                throwOnError: false,
-                displayMode: false
-              }
-            ] as any] : []),
-            rehypeReact
-          ]}
-          skipHtml={false}
-          // Memoize the components object to prevent unnecessary re-renders of ReactMarkdown children
-          components={useMemo(() => ({
-            code: (props: any) => ( // Add type annotation if needed, e.g., props: CodeProps from 'react-markdown/lib/ast-to-react'
-              <CodeHighlight
-                {...props}
-                renderAsDiagram={message.mermaidRendered ?? false}
-              />
-            ),
-            p: ({ children }: { children?: ReactNode }) => <p className="my-2">{children}</p>,
-            h1: ({ children }: { children?: ReactNode }) => <h1 className="text-xl font-bold mt-4 mb-2">{children}</h1>,
-            h2: ({ children }: { children?: ReactNode }) => <h2 className="text-lg font-bold mt-4 mb-2">{children}</h2>,
-            h3: ({ children }: { children?: ReactNode }) => <h3 className="text-base font-bold mt-3 mb-2">{children}</h3>,
-            h4: ({ children }: { children?: ReactNode }) => <h4 className="text-base font-semibold mt-3 mb-2">{children}</h4>,
-            ul: ({ children }: { children?: ReactNode }) => <ul className="list-disc pl-5 my-2">{children}</ul>,
-            ol: ({ children }: { children?: ReactNode }) => <ol className="list-decimal pl-5 my-2">{children}</ol>,
-            li: ({ children }: { children?: ReactNode }) => <li className="my-1">{children}</li>
-          }), [message.mermaidRendered])} // Dependency ensures update if mermaid state changes
-        >
-          {message.content}
-        </ReactMarkdown>
-        {message.role === 'assistant' && message.content && message.content.length > 0 && ( // Added check for message.content existence
-          <Button
-            onClick={handleCopyMarkdown}
-            className="absolute right-0 bottom-0 size-6 rounded-md opacity-20 transition-opacity hover:opacity-100"
-            tooltip={t('retrievePanel.chatMessage.copyTooltip')}
-            variant="default"
-            size="icon"
+      {/* Thinking process display - only for assistant messages */}
+      {message.role === 'assistant' && (isThinking || thinkingTime !== null) && (
+        <div className="mb-2">
+          <div
+            className="flex items-center text-gray-500 dark:text-gray-400 hover:text-gray-700 dark:hover:text-gray-200 transition-colors duration-200 text-sm cursor-pointer select-none"
+            onClick={() => setIsThinkingExpanded(!isThinkingExpanded)}
           >
-            <CopyIcon className="size-4" /> {/* Explicit size */}
-          </Button>
-        )}
-      </div>
-      {message.content === '' && <LoaderIcon className="animate-spin duration-2000" />} {/* Check for empty string specifically */}
+            {isThinking ? (
+              <>
+                <LoaderIcon className="mr-2 size-4 animate-spin" />
+                <span>{t('retrievePanel.chatMessage.thinking')}</span>
+              </>
+            ) : (
+              typeof thinkingTime === 'number' && <span>{t('retrievePanel.chatMessage.thinkingTime', { time: thinkingTime })}</span>
+            )}
+            {finalThinkingContent && <ChevronDownIcon className={`ml-2 size-4 shrink-0 transition-transform ${isThinkingExpanded ? 'rotate-180' : ''}`} />}
+          </div>
+          {isThinkingExpanded && finalThinkingContent && (
+            <div className="mt-2 pl-4 border-l-2 border-primary/20 text-sm prose dark:prose-invert max-w-none break-words prose-p:my-1 prose-headings:my-2">
+              <ReactMarkdown
+                remarkPlugins={[remarkGfm, remarkMath]}
+                rehypePlugins={[
+                  ...(katexPlugin ? [[katexPlugin, { errorColor: theme === 'dark' ? '#ef4444' : '#dc2626', throwOnError: false, displayMode: false }] as any] : []),
+                  rehypeReact
+                ]}
+                skipHtml={false}
+                components={thinkingMarkdownComponents}
+              >
+                {finalThinkingContent}
+              </ReactMarkdown>
+            </div>
+          )}
+        </div>
+      )}
+      {/* Main content display */}
+      {finalDisplayContent && (
+        <div className="relative">
+          <ReactMarkdown
+            className="prose dark:prose-invert max-w-none text-sm break-words prose-headings:mt-4 prose-headings:mb-2 prose-p:my-2 prose-ul:my-2 prose-ol:my-2 prose-li:my-1 [&_.katex]:text-current [&_.katex-display]:my-4 [&_.katex-display]:overflow-x-auto"
+            remarkPlugins={[remarkGfm, remarkMath]}
+            rehypePlugins={[
+              ...(katexPlugin ? [[
+                katexPlugin,
+                {
+                  errorColor: theme === 'dark' ? '#ef4444' : '#dc2626',
+                  throwOnError: false,
+                  displayMode: false
+                }
+              ] as any] : []),
+              rehypeReact
+            ]}
+            skipHtml={false}
+            components={mainMarkdownComponents}
+          >
+            {finalDisplayContent}
+          </ReactMarkdown>
+          {message.role === 'assistant' && finalDisplayContent && finalDisplayContent.length > 0 && (
+            <Button
+              onClick={handleCopyMarkdown}
+              className="absolute right-0 bottom-0 size-6 rounded-md opacity-20 transition-opacity hover:opacity-100"
+              tooltip={t('retrievePanel.chatMessage.copyTooltip')}
+              variant="default"
+              size="icon"
+            >
+              <CopyIcon className="size-4" /> {/* Explicit size */}
+            </Button>
+          )}
+        </div>
+      )}
+      {message.content === '' && !isThinking && !thinkingTime && <LoaderIcon className="animate-spin duration-2000" />} {/* Check for empty string specifically */}
     </div>
   )
 }
diff --git a/lightrag_webui/src/features/RetrievalTesting.tsx b/lightrag_webui/src/features/RetrievalTesting.tsx
index 0744ae5e..288dfeae 100644
--- a/lightrag_webui/src/features/RetrievalTesting.tsx
+++ b/lightrag_webui/src/features/RetrievalTesting.tsx
@@ -58,6 +58,7 @@ export default function RetrievalTesting() {
   const [inputError, setInputError] = useState('') // Error message for input
   // Reference to track if we should follow scroll during streaming (using ref for synchronous updates)
   const shouldFollowScrollRef = useRef(true)
+  const thinkingStartTime = useRef<number | null>(null)
   // Reference to track if user interaction is from the form area
   const isFormInteractionRef = useRef(false)
   // Reference to track if scroll was triggered programmatically
@@ -153,6 +154,39 @@ export default function RetrievalTesting() {
       const updateAssistantMessage = (chunk: string, isError?: boolean) => {
         assistantMessage.content += chunk
 
+        // Start thinking timer on first sight of think tag
+        if (assistantMessage.content.includes('<think>') && !thinkingStartTime.current) {
+          thinkingStartTime.current = Date.now()
+        }
+
+        // Real-time parsing for streaming
+        const thinkStartTag = '<think>';
+        const thinkEndTag = '</think>';
+        const thinkStartIndex = assistantMessage.content.indexOf(thinkStartTag);
+        const thinkEndIndex = assistantMessage.content.indexOf(thinkEndTag);
+
+        if (thinkStartIndex !== -1) {
+          if (thinkEndIndex !== -1) {
+            // Thinking has finished for this chunk, calculate time now
+            assistantMessage.isThinking = false
+            if (thinkingStartTime.current && !assistantMessage.thinkingTime) {
+              const duration = (Date.now() - thinkingStartTime.current) / 1000
+              assistantMessage.thinkingTime = parseFloat(duration.toFixed(2))
+            }
+            assistantMessage.thinkingContent = assistantMessage.content.substring(thinkStartIndex + thinkStartTag.length, thinkEndIndex).trim()
+            assistantMessage.displayContent = assistantMessage.content.substring(thinkEndIndex + thinkEndTag.length).trim()
+          } else {
+            // Still thinking
+            assistantMessage.isThinking = true;
+            assistantMessage.thinkingContent = assistantMessage.content.substring(thinkStartIndex + thinkStartTag.length);
+            assistantMessage.displayContent = '';
+          }
+        } else {
+          assistantMessage.isThinking = false;
+          assistantMessage.displayContent = assistantMessage.content;
+        }
+
+
         // Detect if the assistant message contains a complete mermaid code block
         // Simple heuristic: look for ```mermaid ... ```
         const mermaidBlockRegex = /```mermaid\s+([\s\S]+?)```/g
@@ -171,9 +205,12 @@ export default function RetrievalTesting() {
           const newMessages = [...prev]
           const lastMessage = newMessages[newMessages.length - 1]
           if (lastMessage.role === 'assistant') {
-            lastMessage.content = assistantMessage.content
-            lastMessage.isError = isError
-            lastMessage.mermaidRendered = assistantMessage.mermaidRendered
+            lastMessage.content = assistantMessage.content;
+            lastMessage.thinkingContent = assistantMessage.thinkingContent;
+            lastMessage.displayContent = assistantMessage.displayContent;
+            lastMessage.isThinking = assistantMessage.isThinking;
+            lastMessage.isError = isError;
+            lastMessage.mermaidRendered = assistantMessage.mermaidRendered;
           }
           return newMessages
         })
@@ -223,6 +260,19 @@ export default function RetrievalTesting() {
         // Clear loading and add messages to state
         setIsLoading(false)
         isReceivingResponseRef.current = false
+
+        // Final calculation for thinking time, only if not already calculated
+        if (assistantMessage.thinkingContent && thinkingStartTime.current && !assistantMessage.thinkingTime) {
+          const duration = (Date.now() - thinkingStartTime.current) / 1000
+          assistantMessage.thinkingTime = parseFloat(duration.toFixed(2))
+        }
+        // Ensure isThinking is false at the very end
+        assistantMessage.isThinking = false;
+        // Always reset the timer at the end of a query
+        if (thinkingStartTime.current) {
+          thinkingStartTime.current = null;
+        }
+
         useSettingsStore
           .getState()
           .setRetrievalHistory([...prevMessages, userMessage, assistantMessage])
diff --git a/lightrag_webui/src/locales/en.json b/lightrag_webui/src/locales/en.json
index 1c5cf6e9..7590f74c 100644
--- a/lightrag_webui/src/locales/en.json
+++ b/lightrag_webui/src/locales/en.json
@@ -337,7 +337,9 @@
   "retrievePanel": {
     "chatMessage": {
       "copyTooltip": "Copy to clipboard",
-      "copyError": "Failed to copy text to clipboard"
+      "copyError": "Failed to copy text to clipboard",
+      "thinking": "Thinking...",
+      "thinkingTime": "Thinking time {{time}}s"
     },
     "retrieval": {
       "startPrompt": "Start a retrieval by typing your query below",
diff --git a/lightrag_webui/src/locales/zh.json b/lightrag_webui/src/locales/zh.json
index 951090f7..6d6323aa 100644
--- a/lightrag_webui/src/locales/zh.json
+++ b/lightrag_webui/src/locales/zh.json
@@ -337,7 +337,9 @@
   "retrievePanel": {
     "chatMessage": {
       "copyTooltip": "复制到剪贴板",
-      "copyError": "复制文本到剪贴板失败"
+      "copyError": "复制文本到剪贴板失败",
+      "thinking": "正在思考...",
+      "thinkingTime": "思考用时 {{time}} 秒"
     },
     "retrieval": {
       "startPrompt": "输入查询开始检索",