diff --git a/packages/reactivity/src/effect.ts b/packages/reactivity/src/effect.ts
index 6ad693c26c6..836a7d08413 100644
--- a/packages/reactivity/src/effect.ts
+++ b/packages/reactivity/src/effect.ts
@@ -15,6 +15,9 @@ import { warn } from './warning'
 
 export enum EffectFlags {
   ALLOW_RECURSE = 1 << 2,
+  PAUSED = 1 << 3,
+  NOTIFIED = 1 << 4,
+  STOP = 1 << 5,
 }
 
 export type EffectScheduler = (...args: any[]) => any
@@ -47,13 +50,6 @@ export interface ReactiveEffectRunner<T = any> {
   effect: ReactiveEffect
 }
 
-export enum PauseLevels {
-  None = 0,
-  Paused = 1,
-  Notify = 2,
-  Stop = 3,
-}
-
 export class ReactiveEffect<T = any> implements IEffect, ReactiveEffectOptions {
   nextNotify: IEffect | undefined = undefined
 
@@ -62,8 +58,6 @@ export class ReactiveEffect<T = any> implements IEffect, ReactiveEffectOptions {
   depsTail: Link | undefined = undefined
   flags: number = SubscriberFlags.Dirty
 
-  pauseLevel: PauseLevels = PauseLevels.None
-
   /**
    * @internal
    */
@@ -83,31 +77,32 @@ export class ReactiveEffect<T = any> implements IEffect, ReactiveEffectOptions {
   }
 
   get active(): boolean {
-    return this.pauseLevel !== PauseLevels.Stop
+    return !(this.flags & EffectFlags.STOP)
   }
 
   pause(): void {
-    if (this.pauseLevel === PauseLevels.None) {
-      this.pauseLevel = PauseLevels.Paused
+    if (!(this.flags & EffectFlags.PAUSED)) {
+      this.flags |= EffectFlags.PAUSED
     }
   }
 
   resume(): void {
-    const pauseLevel = this.pauseLevel
-    if (pauseLevel === PauseLevels.Notify) {
-      this.pauseLevel = PauseLevels.None
+    const flags = this.flags
+    if (flags & EffectFlags.PAUSED) {
+      this.flags &= ~EffectFlags.PAUSED
+    }
+    if (flags & EffectFlags.NOTIFIED) {
+      this.flags &= ~EffectFlags.NOTIFIED
       this.notify()
-    } else if (pauseLevel === PauseLevels.Paused) {
-      this.pauseLevel = PauseLevels.None
     }
   }
 
   notify(): void {
-    const pauseLevel = this.pauseLevel
-    if (pauseLevel === PauseLevels.None) {
+    const flags = this.flags
+    if (!(flags & EffectFlags.PAUSED)) {
       this.scheduler()
-    } else if (pauseLevel === PauseLevels.Paused) {
-      this.pauseLevel = PauseLevels.Notify
+    } else {
+      this.flags |= EffectFlags.NOTIFIED
     }
   }
 
@@ -157,7 +152,7 @@ export class ReactiveEffect<T = any> implements IEffect, ReactiveEffectOptions {
       endTrack(this)
       cleanupEffect(this)
       this.onStop && this.onStop()
-      this.pauseLevel = PauseLevels.Stop
+      this.flags |= EffectFlags.STOP
     }
   }
 
diff --git a/packages/reactivity/src/effectScope.ts b/packages/reactivity/src/effectScope.ts
index 76af1bddb80..b03cbc2800f 100644
--- a/packages/reactivity/src/effectScope.ts
+++ b/packages/reactivity/src/effectScope.ts
@@ -1,4 +1,4 @@
-import { PauseLevels, type ReactiveEffect, nextTrackId } from './effect'
+import { EffectFlags, type ReactiveEffect, nextTrackId } from './effect'
 import {
   type Link,
   type Subscriber,
@@ -14,7 +14,7 @@ export class EffectScope implements Subscriber {
   // Subscriber: In order to collect orphans computeds
   deps: Link | undefined = undefined
   depsTail: Link | undefined = undefined
-  flags: SubscriberFlags = SubscriberFlags.None
+  flags: number = SubscriberFlags.None
 
   trackId: number = nextTrackId()
 
@@ -27,8 +27,6 @@ export class EffectScope implements Subscriber {
    */
   cleanups: (() => void)[] = []
 
-  private pauseLevel: PauseLevels = PauseLevels.None
-
   /**
    * only assigned by undetached scope
    * @internal
@@ -57,12 +55,12 @@ export class EffectScope implements Subscriber {
   }
 
   get active(): boolean {
-    return this.pauseLevel !== PauseLevels.Stop
+    return !(this.flags & EffectFlags.STOP)
   }
 
   pause(): void {
-    if (this.pauseLevel === PauseLevels.None) {
-      this.pauseLevel = PauseLevels.Paused
+    if (!(this.flags & EffectFlags.PAUSED)) {
+      this.flags |= EffectFlags.PAUSED
       let i, l
       if (this.scopes) {
         for (i = 0, l = this.scopes.length; i < l; i++) {
@@ -79,8 +77,8 @@ export class EffectScope implements Subscriber {
    * Resumes the effect scope, including all child scopes and effects.
    */
   resume(): void {
-    if (this.pauseLevel === PauseLevels.Paused) {
-      this.pauseLevel = PauseLevels.None
+    if (this.flags & EffectFlags.PAUSED) {
+      this.flags &= ~EffectFlags.PAUSED
       let i, l
       if (this.scopes) {
         for (i = 0, l = this.scopes.length; i < l; i++) {
@@ -125,7 +123,7 @@ export class EffectScope implements Subscriber {
 
   stop(fromParent?: boolean): void {
     if (this.active) {
-      this.pauseLevel = PauseLevels.Stop
+      this.flags |= EffectFlags.STOP
       startTrack(this)
       endTrack(this)
       let i, l
diff --git a/packages/reactivity/src/system.ts b/packages/reactivity/src/system.ts
index 69c1bb20157..7fed1602264 100644
--- a/packages/reactivity/src/system.ts
+++ b/packages/reactivity/src/system.ts
@@ -39,14 +39,15 @@ export enum SubscriberFlags {
   Tracking = 1 << 0,
   CanPropagate = 1 << 1,
   // RunInnerEffects = 1 << 2, // Not used in Vue
-  ToCheckDirty = 1 << 3,
-  Dirty = 1 << 4,
+  // 2~5 are using in EffectFlags
+  ToCheckDirty = 1 << 6,
+  Dirty = 1 << 7,
   Dirtys = SubscriberFlags.ToCheckDirty | SubscriberFlags.Dirty,
   All = SubscriberFlags.Tracking |
     SubscriberFlags.CanPropagate |
     SubscriberFlags.Dirtys,
 
-  DirtyFlagsIndex = 3,
+  DirtyFlagsIndex = 6,
 }
 
 let batchDepth = 0