diff --git a/app/build.gradle b/app/build.gradle
index 40adf01..dbf7c23 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -27,6 +27,8 @@
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
     // Retrofit
     implementation "com.squareup.retrofit2:retrofit:2.5.0"
+    //Jackson
+    implementation 'com.squareup.retrofit2:converter-jackson:2.5.0'
     //QRコードリーダー
     implementation 'com.journeyapps:zxing-android-embedded:3.6.0'
     implementation 'com.android.support:design:28.0.0'
diff --git a/app/src/main/java/com/example/cosmosclient/views/SignupActivity.java b/app/src/main/java/com/example/cosmosclient/views/SignupActivity.java
index 4216f00..451b52f 100644
--- a/app/src/main/java/com/example/cosmosclient/views/SignupActivity.java
+++ b/app/src/main/java/com/example/cosmosclient/views/SignupActivity.java
@@ -9,6 +9,13 @@
 
 import com.example.cosmosclient.R;
 
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+import retrofit2.Retrofit;
+import retrofit2.converter.jackson.JacksonConverterFactory;
+
 public class SignupActivity extends AppCompatActivity {
 
     @Override
@@ -16,6 +23,16 @@
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_signup);
 
+        //retrofitの処理
+        Retrofit retrofit = new Retrofit.Builder()
+                .baseUrl("http://cyberjapandata2.gsi.go.jp/")
+                .addConverterFactory(JacksonConverterFactory.create())
+                .build();
+        Signup signup = retrofit.create(Signup.class);
+
+        //finalつけないとエラー出る
+        final Call<User> call = signup.listUser("1d","2d","3");
+
         //各種idを取得
         Button LoginButton = findViewById(R.id.LoginButton);
         Button MakeAccountButton = findViewById(R.id.MakeAccountButton);
@@ -28,6 +45,22 @@
             @Override
             public void onClick(View v){
                 Intent intent = new Intent(getApplication(), GroupList.class);
+                call.enqueue(new Callback<User>() {
+                    //成功時
+                    @Override
+                    public void onResponse(Call<User> call, Response<User> response) {
+                        if (response.isSuccessful()) {
+                            User result = response.body();
+                        }
+                    }
+
+                    //失敗時
+                    @Override
+                    public void onFailure(Call<User> call, Throwable t) {
+                        t.printStackTrace();
+                    }
+
+                });
                 startActivity(intent);
                 finish();
             }