diff --git a/src/test/java/com/acquirex/cardapproval/CardAcquisitionApprovalApplicationTests.java b/src/test/java/com/acquirex/cardapproval/CardAcquisitionApprovalApplicationTests.java
new file mode 100644
index 0000000..c42210f
--- /dev/null
+++ b/src/test/java/com/acquirex/cardapproval/CardAcquisitionApprovalApplicationTests.java
@@ -0,0 +1,145 @@
+package com.acquirex.cardapproval;
+
+import com.acquirex.cardapproval.domain.AcquisitionApproval;
+import com.acquirex.cardapproval.domain.AcquisitionApproval.ApprovalStatus;
+import com.acquirex.cardapproval.domain.AcquisitionApprovalRepository;
+import com.acquirex.cardapproval.service.AcquisitionApprovalService;
+import com.acquirex.cardapproval.service.AcquisitionApprovalService.AcquisitionApprovalException;
+import com.acquirex.cardapproval.service.AcquisitionApprovalService.AcquisitionApprovalRequest;
+import com.acquirex.cardapproval.service.AcquisitionApprovalService.AcquisitionApprovalResponse;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.math.BigDecimal;
+import java.time.LocalDateTime;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+/**
+ * Spring Boot 3.x 카드 매입 승인 서비스 통합 테스트
+ */
+@SpringBootTest
+@ActiveProfiles("test")
+@Transactional
+class CardAcquisitionApprovalApplicationTests {
+
+    @Autowired
+    private AcquisitionApprovalService service;
+
+    @Autowired
+    private AcquisitionApprovalRepository repository;
+
+    private AcquisitionApprovalRequest validRequest;
+
+    @BeforeEach
+    void setUp() {
+        validRequest = AcquisitionApprovalRequest.builder()
+                .merchantId("MERCHANT001")
+                .cardNumber("1234567890123456")
+                .acquisitionAmount(new BigDecimal("50000"))
+                .approvalAmount(new BigDecimal("50000"))
+                .approvalNumber("APPR" + System.currentTimeMillis())
+                .acquisitionDatetime(LocalDateTime.now())
+                .build();
+    }
+
+    @Test
+    @DisplayName("애플리케이션 컨텍스트 로드 성공")
+    void contextLoads() {
+        assertThat(service).isNotNull();
+        assertThat(repository).isNotNull();
+    }
+
+    @Test
+    @DisplayName("매입 승인 요청 처리 성공")
+    void processAcquisition_Success() {
+        AcquisitionApprovalResponse response = service.processAcquisition(validRequest);
+
+        assertThat(response).isNotNull();
+        assertThat(response.getId()).isNotNull();
+        assertThat(response.getMerchantId()).isEqualTo("MERCHANT001");
+        assertThat(response.getApprovalStatus()).isEqualTo(ApprovalStatus.APPROVED);
+        assertThat(response.getCancelYn()).isEqualTo("N");
+    }
+
+    @Test
+    @DisplayName("매입 금액과 승인 금액 불일치 시 예외 발생")
+    void processAcquisition_AmountMismatch_ThrowsException() {
+        validRequest.setApprovalAmount(new BigDecimal("40000"));
+
+        assertThatThrownBy(() -> service.processAcquisition(validRequest))
+                .isInstanceOf(AcquisitionApprovalException.class)
+                .hasFieldOrPropertyWithValue("errorCode", "AMOUNT_MISMATCH");
+    }
+
+    @Test
+    @DisplayName("매입 취소 처리 성공")
+    void cancelAcquisition_Success() {
+        AcquisitionApprovalResponse created = service.processAcquisition(validRequest);
+        AcquisitionApprovalResponse cancelled = service.cancelAcquisition(created.getId(), "고객 요청");
+
+        assertThat(cancelled.getCancelYn()).isEqualTo("Y");
+        assertThat(cancelled.getApprovalStatus()).isEqualTo(ApprovalStatus.CANCELLED);
+        assertThat(cancelled.getCancelReason()).isEqualTo("고객 요청");
+        assertThat(cancelled.getCancelDatetime()).isNotNull();
+    }
+
+    @Test
+    @DisplayName("이미 취소된 건 재취소 시 예외 발생")
+    void cancelAcquisition_AlreadyCancelled_ThrowsException() {
+        AcquisitionApprovalResponse created = service.processAcquisition(validRequest);
+        service.cancelAcquisition(created.getId(), "첫 번째 취소");
+
+        assertThatThrownBy(() -> service.cancelAcquisition(created.getId(), "두 번째 취소"))
+                .isInstanceOf(AcquisitionApprovalException.class)
+                .hasFieldOrPropertyWithValue("errorCode", "ALREADY_CANCELLED");
+    }
+
+    @Test
+    @DisplayName("존재하지 않는 매입 승인 조회 시 예외 발생")
+    void getAcquisition_NotFound_ThrowsException() {
+        assertThatThrownBy(() -> service.getAcquisition(99999L))
+                .isInstanceOf(AcquisitionApprovalException.class)
+                .hasFieldOrPropertyWithValue("errorCode", "NOT_FOUND");
+    }
+
+    @Test
+    @DisplayName("가맹점별 매입 승인 목록 조회 성공")
+    void getAcquisitionsByMerchant_Success() {
+        service.processAcquisition(validRequest);
+
+        List<AcquisitionApprovalResponse> responses = service.getAcquisitionsByMerchant("MERCHANT001");
+
+        assertThat(responses).isNotEmpty();
+        assertThat(responses).allMatch(r -> r.getMerchantId().equals("MERCHANT001"));
+    }
+
+    @Test
+    @DisplayName("엔티티 취소 메서드 동작 확인")
+    void entityCancelMethod_WorksCorrectly() {
+        AcquisitionApproval approval = AcquisitionApproval.builder()
+                .merchantId("TEST")
+                .cardNumber("1234")
+                .acquisitionAmount(new BigDecimal("1000"))
+                .approvalAmount(new BigDecimal("1000"))
+                .approvalNumber("TEST001")
+                .acquisitionDatetime(LocalDateTime.now())
+                .approvalStatus(ApprovalStatus.APPROVED)
+                .cancelYn("N")
+                .build();
+
+        approval.cancel("테스트 취소");
+
+        assertThat(approval.getCancelYn()).isEqualTo("Y");
+        assertThat(approval.getCancelReason()).isEqualTo("테스트 취소");
+        assertThat(approval.getCancelDatetime()).isNotNull();
+        assertThat(approval.getApprovalStatus()).isEqualTo(ApprovalStatus.CANCELLED);
+    }
+}
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