diff --git a/app/src/main/java/com/example/tampopo_client/viewmodels/ActivityViewModel.java b/app/src/main/java/com/example/tampopo_client/viewmodels/ActivityViewModel.java
index 2f7d914..72d5f07 100644
--- a/app/src/main/java/com/example/tampopo_client/viewmodels/ActivityViewModel.java
+++ b/app/src/main/java/com/example/tampopo_client/viewmodels/ActivityViewModel.java
@@ -1,21 +1,84 @@
 package com.example.tampopo_client.viewmodels;
 
+import android.util.Log;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
 
+import com.example.tampopo_client.models.Activity;
 import com.example.tampopo_client.resources.ActivitiesResource;
 
+import java.util.ArrayList;
+import java.util.List;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
 import retrofit2.Retrofit;
 import retrofit2.converter.jackson.JacksonConverterFactory;
 
+/**
+ * アクティビティを扱うためのViewModel
+ *
+ * @author Shohei Yamagiwa
+ * @implNote Repositoryは作成せずに、すべてViewModelで処理する
+ */
 public class ActivityViewModel extends ViewModel {
-    private final Retrofit retrofit;
     private final ActivitiesResource activitiesResource;
 
+    private final MutableLiveData<List<Activity>> activitiesLiveData;
+
     public ActivityViewModel() {
-        retrofit = new Retrofit.Builder()
+        final Retrofit retrofit = new Retrofit.Builder()
                 .baseUrl("http://nitta-lab-www.is.konan-u.ac.jp/tampopo-server/")
                 .addConverterFactory(JacksonConverterFactory.create())
                 .build();
         activitiesResource = retrofit.create(ActivitiesResource.class);
+
+        activitiesLiveData = new MutableLiveData<>(List.of());
+    }
+
+    public void createActivity(String userId, String token, String newActivity) {
+        Call<String> createActivityCall = activitiesResource.addActivity(userId, token, newActivity);
+        createActivityCall.enqueue(new Callback<String>() {
+            @Override
+            public void onResponse(@NonNull Call<String> call, @NonNull Response<String> response) {
+                if (response.isSuccessful()) {
+                    String createdActivityId = response.body();
+
+                    // TODO: 仮作成なので改善必須
+                    Call<Activity> getActivityCall = activitiesResource.getActivity(userId, createdActivityId);
+                    getActivityCall.enqueue(new Callback<Activity>() {
+                        @Override
+                        public void onResponse(@NonNull Call<Activity> call, @NonNull Response<Activity> response) {
+                            List<Activity> activities = activitiesLiveData.getValue();
+                            if (activities == null) {
+                                activities = new ArrayList<>();
+                            }
+                            Activity createdActivity = response.body();
+                            activities.add(createdActivity);
+                            activitiesLiveData.postValue(activities);
+                        }
+
+                        @Override
+                        public void onFailure(@NonNull Call<Activity> call, @NonNull Throwable t) {
+                            Log.e(ActivityViewModel.class.getSimpleName(), "An error has occurred.", t);
+                        }
+                    });
+                } else {
+                    Log.e(ActivityViewModel.class.getSimpleName(), response.code() + " " + response.message());
+                }
+            }
+
+            @Override
+            public void onFailure(@NonNull Call<String> call, @NonNull Throwable t) {
+                Log.e(ActivityViewModel.class.getSimpleName(), "An error has occurred.", t);
+            }
+        });
+    }
+
+    public MutableLiveData<List<Activity>> getActivitiesLiveData() {
+        return activitiesLiveData;
     }
 }