diff --git a/application-test/app-test/pom.xml b/application-test/app-test/pom.xml
index 3b1eb24f..e6d23bb4 100644
--- a/application-test/app-test/pom.xml
+++ b/application-test/app-test/pom.xml
@@ -30,9 +30,10 @@
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
         <dependency>
-            <groupId>com.h2database</groupId>
-            <artifactId>h2</artifactId>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
         </dependency>
+
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
@@ -43,6 +44,25 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>1.15.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>postgresql</artifactId>
+            <version>1.15.2</version>
+            <scope>test</scope>
+        </dependency>
+
+
 
         <dependency>
             <groupId>org.junit.vintage</groupId>
diff --git a/application-test/app-test/src/main/java/com/example/apptest/App.java b/application-test/app-test/src/main/java/com/example/apptest/App.java
new file mode 100644
index 00000000..f0848458
--- /dev/null
+++ b/application-test/app-test/src/main/java/com/example/apptest/App.java
@@ -0,0 +1,12 @@
+package com.example.apptest;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class App {
+
+    public static void main(String[] args) {
+        SpringApplication.run(App.class, args);
+    }
+}
diff --git a/application-test/app-test/src/main/java/com/example/apptest/domain/Study.java b/application-test/app-test/src/main/java/com/example/apptest/domain/Study.java
index 8984f0bb..2f9c88b9 100644
--- a/application-test/app-test/src/main/java/com/example/apptest/domain/Study.java
+++ b/application-test/app-test/src/main/java/com/example/apptest/domain/Study.java
@@ -20,7 +20,7 @@ public class Study {
 
     private StudyStatus status = StudyStatus.DRAFT;
 
-    private int limit;
+    private int limitCount;
 
     private String name;
 
@@ -29,7 +29,7 @@ public class Study {
     private Long ownerId;
 
     public Study(int limit, String name) {
-        this.limit = limit;
+        this.limitCount = limit;
         this.name = name;
     }
 
@@ -37,7 +37,7 @@ public class Study {
         if (limit <= 0) {
             throw new IllegalArgumentException("limit은 0보다 커야 한다.");
         }
-        this.limit = limit;
+        this.limitCount = limit;
     }
 
     public void open() {
diff --git a/application-test/app-test/src/main/java/com/example/apptest/study/StudyService.java b/application-test/app-test/src/main/java/com/example/apptest/study/StudyService.java
index f46f74c1..a756af24 100644
--- a/application-test/app-test/src/main/java/com/example/apptest/study/StudyService.java
+++ b/application-test/app-test/src/main/java/com/example/apptest/study/StudyService.java
@@ -25,4 +25,12 @@ public class StudyService {
         memberService.notify(member);
         return newStudy;
     }
+
+    public Study openStudy(Study study) {
+        study.open();
+        Study openedStudy = studyRepository.save(study);
+        memberService.notify(openedStudy);
+        return openedStudy;
+    }
+
 }
diff --git a/application-test/app-test/src/main/resources/application.yml b/application-test/app-test/src/main/resources/application.yml
index 53372abf..22eeb9ad 100644
--- a/application-test/app-test/src/main/resources/application.yml
+++ b/application-test/app-test/src/main/resources/application.yml
@@ -1,14 +1,8 @@
 spring:
-  h2:
-    console:
-      enabled: true
-      path: /h2-console
-
   datasource:
-    url: jdbc:h2:mem:testDb
-    driver-class-name: org.h2.Driver
-    username: sa
-    password:
+    url: jdbc:postgresql://localhost:5432/study
+    username: study
+    password: study
 
   jpa:
     hibernate:
diff --git a/application-test/app-test/src/test/java/com/example/apptest/study/StudyServiceSpringBootTest.java b/application-test/app-test/src/test/java/com/example/apptest/study/StudyServiceSpringBootTest.java
new file mode 100644
index 00000000..f1f45d04
--- /dev/null
+++ b/application-test/app-test/src/test/java/com/example/apptest/study/StudyServiceSpringBootTest.java
@@ -0,0 +1,47 @@
+package com.example.apptest.study;
+
+import com.example.apptest.domain.Member;
+import com.example.apptest.domain.Study;
+import com.example.apptest.member.MemberService;
+import org.junit.jupiter.api.*;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+import org.testcontainers.containers.PostgreSQLContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.then;
+import static org.mockito.Mockito.times;
+
+@SpringBootTest
+@ExtendWith(MockitoExtension.class)
+@ActiveProfiles("test")
+@Testcontainers
+public class StudyServiceSpringBootTest {
+
+    @Mock MemberService memberService;
+    @Autowired StudyRepository studyRepository;
+
+    @Container
+    static PostgreSQLContainer<?> postgreSQLContainer =
+            new PostgreSQLContainer<>().withDatabaseName("studytest");
+
+    @BeforeEach
+    void beforeEach() {
+        studyRepository.deleteAll();
+    }
+
+    @Test
+    void test_51() {
+        System.out.println("테스트 완료!!");
+    }
+}
diff --git a/application-test/app-test/src/test/java/com/example/apptest/study/StudyServiceTest.java b/application-test/app-test/src/test/java/com/example/apptest/study/StudyServiceTest.java
index 616e4558..cdf663c3 100644
--- a/application-test/app-test/src/test/java/com/example/apptest/study/StudyServiceTest.java
+++ b/application-test/app-test/src/test/java/com/example/apptest/study/StudyServiceTest.java
@@ -2,6 +2,7 @@ package com.example.apptest.study;
 
 import com.example.apptest.domain.Member;
 import com.example.apptest.domain.Study;
+import com.example.apptest.domain.StudyStatus;
 import com.example.apptest.member.MemberService;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -22,6 +23,31 @@ import static org.mockito.Mockito.*;
 @ExtendWith(MockitoExtension.class)
 class StudyServiceTest {
 
+    @DisplayName("다른 사용자가 볼 수 있도록 스터디를 공개한다.")
+    @Test
+    void test_50(@Mock MemberService memberService,
+                 @Mock StudyRepository studyRepository) {
+        // Given
+        StudyService studyService = new StudyService(memberService, studyRepository);
+        Study study = new Study(10, "더 자바, 테스트");
+        assertNull(study.getOpenedDateTime());
+        // TODO studyRepository Mock 객체의 save 메소드를호출 시 study를 리턴하도록 만들기.
+        given(studyRepository.save(study)).willReturn(study);
+
+        // When
+        studyService.openStudy(study);
+
+        // Then
+        // TODO study의 status가 OPENED로 변경됐는지 확인
+        assertEquals(StudyStatus.OPENED, study.getStatus());
+        // TODO study의 openedDataTime이 null이 아닌지 확인
+        assertNotNull(study.getOpenedDateTime());
+        // TODO memberService의 notify(study)가 호출 됐는지 확인.
+        then(memberService).should().notify(study);
+
+        System.out.println("테스트 완료!");
+    }
+
     @Test
     @DisplayName("BDD style test")
     void test_49(@Mock MemberService memberService,
diff --git a/application-test/app-test/src/test/resources/application-test.yml b/application-test/app-test/src/test/resources/application-test.yml
new file mode 100644
index 00000000..5975c10d
--- /dev/null
+++ b/application-test/app-test/src/test/resources/application-test.yml
@@ -0,0 +1,8 @@
+spring:
+  datasource:
+    url: jdbc:tc:postgresql:///studytest
+    driver-class-name: org.testcontainers.jdbc.ContainerDatabaseDriver
+
+  jpa:
+    hibernate:
+      ddl-auto: create-drop
\ No newline at end of file