diff --git a/app/src/main/java/com/najudoryeong/mineme/MainActivity.kt b/app/src/main/java/com/najudoryeong/mineme/MainActivity.kt
index 7fa77e0..175ebb1 100644
--- a/app/src/main/java/com/najudoryeong/mineme/MainActivity.kt
+++ b/app/src/main/java/com/najudoryeong/mineme/MainActivity.kt
@@ -2,33 +2,56 @@ package com.najudoryeong.mineme
 
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import androidx.activity.viewModels
 import androidx.databinding.DataBindingUtil
+import androidx.databinding.Observable
+import androidx.lifecycle.Observer
+import androidx.navigation.Navigation
+import androidx.navigation.findNavController
 import androidx.navigation.fragment.NavHostFragment
+import androidx.navigation.ui.AppBarConfiguration
+import androidx.navigation.ui.NavigationUI
 import androidx.navigation.ui.setupWithNavController
+import com.najudoryeong.mineme.common_ui.MainViewModelUtil
 import com.najudoryeong.mineme.databinding.ActivityMainBinding
 
-
-class MainActivity : AppCompatActivity() {
+// 하위 모듈이 MainViewModel 코드에 접근할 수 있게 MainViewModelUtil 상속 구현
+class MainActivity : AppCompatActivity(), MainViewModelUtil {
 
     private lateinit var binding: ActivityMainBinding
+    private lateinit var appBarConfiguration: AppBarConfiguration
+    private val model: MainViewModel by viewModels()
 
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
+
+        binding.viewModel = model
+        model.toolbarTitle.observe(this, toolbarTitleObserver)
+
         initAppBar()
         initBottomNav()
     }
 
     private fun initBottomNav() {
-        val navHostFragment = supportFragmentManager.findFragmentById(R.id.fragment_containerView) as NavHostFragment
+        val navHostFragment =
+            supportFragmentManager.findFragmentById(R.id.fragment_containerView) as NavHostFragment
         val navController = navHostFragment.navController
 
-        binding.bottomNavigationView.let {
-            it.setupWithNavController(navController)
-            it.itemIconTintList = null
-        }
+        // appbar 구성 요소 설정
+        // 바텀네비게이션과 연결하면 해당 프래그먼트에 네비게이션으로는 backButton x
+        appBarConfiguration = AppBarConfiguration(
+            setOf(R.id.storyFragment)
+        )
+
+        // navController와 actionbar 연결
+        NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration)
 
+        binding.bottomNavigationView.run {
+            setupWithNavController(navController)
+            itemIconTintList = null
+        }
     }
 
     private fun initAppBar() {
@@ -38,4 +61,16 @@ class MainActivity : AppCompatActivity() {
             setDisplayHomeAsUpEnabled(true)
         }
     }
+
+    /** [MainViewModelUtil] */
+    override fun setToolbarTitle(newTitle: String) {
+        model.updateToolbarTitle(newTitle)
+    }
+
+    //toolbar title 옵저버
+    private val toolbarTitleObserver = Observer<String> {
+        binding.toolbar.title = it
+    }
+
+
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/najudoryeong/mineme/MainViewModel.kt b/app/src/main/java/com/najudoryeong/mineme/MainViewModel.kt
index 7c15204..8be94c0 100644
--- a/app/src/main/java/com/najudoryeong/mineme/MainViewModel.kt
+++ b/app/src/main/java/com/najudoryeong/mineme/MainViewModel.kt
@@ -1,7 +1,20 @@
 package com.najudoryeong.mineme
 
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
+import com.najudoryeong.mineme.common_ui.MainViewModelUtil
+
 
 class MainViewModel : ViewModel() {
 
+    private val _toolbarTitle = MutableLiveData<String>()
+
+    val toolbarTitle: LiveData<String>
+        get() = _toolbarTitle
+
+    fun updateToolbarTitle(newTitle: String) {
+        _toolbarTitle.value = newTitle
+    }
+
 }
\ No newline at end of file
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 18bf7ed..eb72f1b 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -3,6 +3,13 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools">
 
+    <data>
+
+        <variable
+            name="viewModel"
+            type="com.najudoryeong.mineme.MainViewModel" />
+    </data>
+
     <androidx.coordinatorlayout.widget.CoordinatorLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
@@ -12,10 +19,11 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content">
 
-            <androidx.appcompat.widget.Toolbar
+            <com.google.android.material.appbar.MaterialToolbar
                 android:id="@+id/toolbar"
                 android:layout_width="match_parent"
-                android:layout_height="?attr/actionBarSize"/>
+                android:layout_height="?attr/actionBarSize"
+                app:titleCentered="true" />
 
         </com.google.android.material.appbar.AppBarLayout>