diff --git a/src/components/Sing/ScoreSequencer.vue b/src/components/Sing/ScoreSequencer.vue
index ca72246881..dabe54c353 100644
--- a/src/components/Sing/ScoreSequencer.vue
+++ b/src/components/Sing/ScoreSequencer.vue
@@ -23,6 +23,8 @@
           :offset="scrollX"
           :numMeasures
         />
+        <!-- ループエリア -->
+        <LoopLane :offset="scrollX" />
         <!-- 鍵盤 -->
         <SequencerKeys
           class="sequencer-keys"
diff --git a/src/components/Sing/SequencerRuler/LoopLane/Container.vue b/src/components/Sing/SequencerRuler/LoopLane/Container.vue
index 99f09f1ab8..000fc63a50 100644
--- a/src/components/Sing/SequencerRuler/LoopLane/Container.vue
+++ b/src/components/Sing/SequencerRuler/LoopLane/Container.vue
@@ -265,6 +265,12 @@ const stopDragging = () => {
   }
 
   try {
+    // ループ範囲が0の場合はクリア
+    if (previewLoopStartTick.value === previewLoopEndTick.value) {
+      void store.actions.COMMAND_CLEAR_LOOP_RANGE();
+      return;
+    }
+
     // ループ範囲を設定
     void store.actions.COMMAND_SET_LOOP_RANGE({
       loopStartTick: previewLoopStartTick.value,
@@ -272,11 +278,9 @@ const stopDragging = () => {
     });
 
     // ループ範囲が有効な場合は再生ヘッドをループ開始位置に移動
-    if (previewLoopStartTick.value !== previewLoopEndTick.value) {
-      void store.actions.SET_PLAYHEAD_POSITION({
-        position: previewLoopStartTick.value,
-      });
-    }
+    void store.actions.SET_PLAYHEAD_POSITION({
+      position: previewLoopStartTick.value,
+    });
   } catch (error) {
     throw new UnreachableError("Failed to set loop range");
   }
diff --git a/src/domain/project/schema.ts b/src/domain/project/schema.ts
index 4b397ef861..bcbe1a6f1c 100644
--- a/src/domain/project/schema.ts
+++ b/src/domain/project/schema.ts
@@ -100,9 +100,9 @@ export const trackSchema = z.object({
 });
 
 export const loopSchema = z.object({
-  isLoopEnabled: z.boolean(),
   startTick: z.number(), // ループ開始ティック
   endTick: z.number(), // ループ終了ティック
+  isLoopEnabled: z.boolean(),
 });
 
 // プロジェクトファイルのスキーマ
@@ -120,11 +120,7 @@ export const projectSchema = z.object({
     timeSignatures: z.array(timeSignatureSchema),
     tracks: z.record(trackIdSchema, trackSchema),
     trackOrder: z.array(trackIdSchema),
-    loop: z.object({
-      startTick: z.number(),
-      endTick: z.number(),
-      isLoopEnabled: z.boolean(),
-    }),
+    loop: loopSchema.optional(),
   }),
 });
 
diff --git a/src/store/project.ts b/src/store/project.ts
index 651edb74d4..579dbc6b0a 100755
--- a/src/store/project.ts
+++ b/src/store/project.ts
@@ -74,10 +74,15 @@ const applySongProjectToStore = async (
       }),
     ),
   });
-  await actions.SET_LOOP_ENABLED({ isLoopEnabled: loop.isLoopEnabled });
+
+  // ループ情報を設定（ない場合はデフォルト値を使用）
+  // TODO: オプショナルチェインを避けたい(プロジェクト関連の仕様がよくわかっていない)
+  await actions.SET_LOOP_ENABLED({
+    isLoopEnabled: loop?.isLoopEnabled ?? false,
+  });
   await actions.SET_LOOP_RANGE({
-    loopStartTick: loop.startTick,
-    loopEndTick: loop.endTick,
+    loopStartTick: loop?.startTick ?? 0,
+    loopEndTick: loop?.endTick ?? 0,
   });
 };