diff --git a/app/src/main/java/com/example/sprout/refactor/activity/BaseActivity.java b/app/src/main/java/com/example/sprout/refactor/activity/BaseActivity.java
new file mode 100644
index 0000000..0edae67
--- /dev/null
+++ b/app/src/main/java/com/example/sprout/refactor/activity/BaseActivity.java
@@ -0,0 +1,78 @@
+package com.example.sprout.refactor.activity;
+
+import android.content.Intent;
+import android.support.v7.app.AppCompatActivity;
+import android.widget.Toast;
+
+import com.example.sprout.refactor.messengers.NavigationMessage;
+import com.example.sprout.refactor.messengers.ToastMessage;
+import com.example.sprout.refactor.notification.Observer;
+import com.example.sprout.refactor.viewmodel.BaseViewModel;
+
+/**
+ * Activityの基底クラス
+ * Created by matsumoto_k on 2017/12/22.
+ */
+public abstract class BaseActivity extends AppCompatActivity {
+
+    /**
+     * 画面遷移のObserver
+     */
+    protected Observer<NavigationMessage> navigationObserver = new Observer<NavigationMessage>() {
+        @Override
+        public void notify(NavigationMessage navigationMessage) {
+            switch (navigationMessage.getType()) {
+                case Start:
+                    startActivity(new Intent(BaseActivity.this, navigationMessage.getClazz()));
+                    break;
+                case Finish:
+                    finish();
+                    break;
+            }
+        }
+
+        @Override
+        public void error(Throwable throwable) {
+
+        }
+    };
+    /**
+     * トーストのObserver
+     */
+    protected Observer<ToastMessage> toastObserver = new Observer<ToastMessage>() {
+        @Override
+        public void notify(ToastMessage toastMessage) {
+            switch (toastMessage.getLength()) {
+                case SHORT:
+                    Toast.makeText(BaseActivity.this, toastMessage.getMessage(), Toast.LENGTH_SHORT).show();
+                    break;
+                case LONG:
+                    Toast.makeText(BaseActivity.this, toastMessage.getMessage(), Toast.LENGTH_LONG).show();
+                    break;
+            }
+        }
+
+        @Override
+        public void error(Throwable throwable) {
+
+        }
+    };
+
+    /**
+     * 引数のObservableに対してobserverを登録する
+     *
+     * @param baseViewModel BaseViewModelを継承したクラスを引数に渡す
+     */
+    protected void addUiObserver(BaseViewModel baseViewModel) {
+        baseViewModel.addObserver(navigationObserver, toastObserver);
+    }
+
+    /**
+     * 引数のObservableに対してobserverを削除する
+     *
+     * @param baseViewModel BaseViewModelを継承したクラスを引数に渡す
+     */
+    protected void removeUiObserver(BaseViewModel baseViewModel) {
+        baseViewModel.removeObserver(navigationObserver, toastObserver);
+    }
+}