diff --git a/src/components/chat/StreamingIndicator.tsx b/src/components/chat/StreamingIndicator.tsx
index a3c236c..3edbb47 100644
--- a/src/components/chat/StreamingIndicator.tsx
+++ b/src/components/chat/StreamingIndicator.tsx
@@ -17,12 +17,9 @@ export function StreamingIndicator(): React.JSX.Element | null {
   if (!isStreaming) return null;
 
   const lastMsg = messages[messages.length - 1];
-  // 仅当最后一条是 assistant 消息且有内容时才隐藏
-  // 如果最后一条是 user 消息（刚发送，等待 AI 响应），应显示加载指示器
-  const isLastAssistant = lastMsg?.role === 'assistant';
-  const hasVisibleContent = isLastAssistant &&
-    (!!lastMsg?.content || !!lastMsg?.reasoningContent || !!lastMsg?.toolCalls?.length);
-  if (hasVisibleContent) return null;
+  // 最后一条是 assistant 消息时隐藏（即使内容为空，AssistantMessage 会显示"正在思考..."）
+  // 仅当最后一条是 user 消息（刚发送，等待 AI 响应）时显示加载指示器
+  if (lastMsg?.role === 'assistant') return null;
 
   return (
     <Box sx={{ display: 'flex', alignItems: 'center', gap: 1.5, py: 2, pl: 5, animation: 'fadeIn 200ms ease-out' }}>
diff --git a/src/components/trace/TraceStep.tsx b/src/components/trace/TraceStep.tsx
index 8a6f686..70dea12 100644
--- a/src/components/trace/TraceStep.tsx
+++ b/src/components/trace/TraceStep.tsx
@@ -64,13 +64,18 @@ export function TraceStep({ step, isCurrent }: TraceStepProps): React.JSX.Elemen
   const label = TRACE_STATE_LABELS[step.state] ?? step.state;
   const duration = step.completedAt ? step.completedAt - step.startedAt : null;
 
+  // 构建状态进度链（如 "思考 → 执行 → 观察"）
+  const stateChain = (step.states ?? [step.state])
+    .map((s) => TRACE_STATE_LABELS[s] ?? s)
+    .join(' → ');
+
   return (
     <Box sx={{ borderRadius: 1, border: '1px solid', borderColor: 'divider', bgcolor: 'secondary.main', transition: 'all 150ms', ...(isCurrent ? { boxShadow: `0 0 0 1px ${color}` } : {}) }}>
       <IconButton size="small" onClick={handleToggle} sx={{ width: '100%', justifyContent: 'flex-start', gap: 1, px: 1.5, py: 1, borderRadius: '4px 4px 0 0', color: 'text.primary', fontSize: 12 }}>
         {expanded ? <ChevronDown size={10} /> : <ChevronRight size={10} />}
         {isCurrent ? <Loader2 size={12} style={{ color, animation: 'spin 1s linear infinite' }} /> : step.completedAt ? <CheckCircle size={12} style={{ color }} /> : <CircleDot size={12} style={{ color }} />}
         <Typography component="span" sx={{ fontWeight: 600, color, fontSize: 12 }}>#{step.iteration}</Typography>
-        <Typography component="span" sx={{ textTransform: 'uppercase', color: 'text.secondary', fontSize: 12 }}>{label}</Typography>
+        <Typography component="span" sx={{ color: 'text.secondary', fontSize: 12 }}>{stateChain}</Typography>
         {duration != null && <Typography variant="caption" sx={{ ml: 'auto', color: 'text.secondary' }}>{formatDuration(duration)}</Typography>}
         {step.tokenUsage && <Typography variant="caption" sx={{ color: 'text.secondary' }}>{formatTokens(step.tokenUsage.totalTokens)} tok</Typography>}
       </IconButton>
diff --git a/src/hooks/useAgentStream.ts b/src/hooks/useAgentStream.ts
index 21fc66a..9f3b8f5 100644
--- a/src/hooks/useAgentStream.ts
+++ b/src/hooks/useAgentStream.ts
@@ -265,29 +265,41 @@ export function useAgentStream(): void {
         }
       }
 
-      // --- Trace 步骤管理（每轮迭代一个步骤，状态转换时更新而非新建）---
+      // --- Trace 步骤管理（每轮迭代一个步骤，状态转换时追加到 states 数组）---
       if (data.state && data.iteration != null) {
-        const traceSteps = store.traceSteps;
-        const lastStep = traceSteps[traceSteps.length - 1];
-
-        // 判断是否需要创建新步骤：同一迭代的首次状态（INIT/THINKING）创建新步骤
-        // 后续状态转换（EXECUTING/OBSERVING等）只更新当前步骤的 state 字段
-        const isSameIteration = lastStep && lastStep.iteration === data.iteration;
-
-        if (isSameIteration) {
-          // 同一迭代内的状态转换 → 更新当前步骤状态
-          store.updateLastTraceStep({ state: data.state });
+        // 跳过 INIT (iteration=0)：引擎初始化阶段无实际内容，不创建 trace step
+        if (data.state === 'INIT' && data.iteration === 0) {
+          // 仍需更新 Agent 状态映射
         } else {
-          // 新迭代 → 标记上一步完成，创建新步骤
-          if (lastStep && !lastStep.completedAt) {
-            store.updateLastTraceStep({ completedAt: Date.now() });
+          const traceSteps = store.traceSteps;
+          const lastStep = traceSteps[traceSteps.length - 1];
+
+          // 判断是否需要创建新步骤：同一迭代的首次状态创建新步骤
+          // 后续状态转换（EXECUTING/OBSERVING等）追加到 states 数组
+          const isSameIteration = lastStep && lastStep.iteration === data.iteration;
+
+          if (isSameIteration) {
+            // 同一迭代内的状态转换 → 追加状态到 states 数组，更新当前 state
+            const currentStates = lastStep.states ?? [lastStep.state];
+            if (currentStates[currentStates.length - 1] !== data.state) {
+              store.updateLastTraceStep({
+                state: data.state,
+                states: [...currentStates, data.state],
+              });
+            }
+          } else {
+            // 新迭代 → 标记上一步完成，创建新步骤
+            if (lastStep && !lastStep.completedAt) {
+              store.updateLastTraceStep({ completedAt: Date.now() });
+            }
+            store.addTraceStep({
+              id: `trace_${data.iteration}_${data.state}_${Date.now()}`,
+              iteration: data.iteration,
+              state: data.state,
+              states: [data.state],
+              startedAt: Date.now(),
+            });
           }
-          store.addTraceStep({
-            id: `trace_${data.iteration}_${data.state}_${Date.now()}`,
-            iteration: data.iteration,
-            state: data.state,
-            startedAt: Date.now(),
-          });
         }
 
         // --- Agent 状态映射 ---
diff --git a/src/stores/agent-store.ts b/src/stores/agent-store.ts
index b6d1430..cb2ac91 100644
--- a/src/stores/agent-store.ts
+++ b/src/stores/agent-store.ts
@@ -59,6 +59,7 @@ export interface TraceStep {
   id: string;
   iteration: number;
   state: string;
+  states: string[];
   startedAt: number;
   completedAt?: number;
   thought?: string;
@@ -163,10 +164,11 @@ export const useAgentStore = create<AgentState>((set, get) => ({
       window.metona.sessions.getTrace(id).then((data) => {
         if (data) {
           if (data.traceSteps) {
-            // 兼容旧数据：为缺少 id 的 trace 步骤生成 id
+            // 兼容旧数据：为缺少 id/states 的 trace 步骤补全
             const steps = (data.traceSteps as TraceStep[]).map((t, i) => ({
               ...t,
               id: t.id ?? `trace_legacy_${t.iteration}_${t.state}_${i}`,
+              states: t.states ?? [t.state],
             }));
             set({ traceSteps: steps });
           }