diff --git a/src/test/java/com/acquirex/ApprovalServiceTest.java b/src/test/java/com/acquirex/ApprovalServiceTest.java
new file mode 100644
index 0000000..5facdf5
--- /dev/null
+++ b/src/test/java/com/acquirex/ApprovalServiceTest.java
@@ -0,0 +1,150 @@
+package com.acquirex;
+
+import com.acquirex.domain.AcquisitionCard;
+import com.acquirex.domain.ApprovalRequest;
+import com.acquirex.dto.ApprovalRequestDto;
+import com.acquirex.dto.ApprovalResponseDto;
+import com.acquirex.repository.AcquisitionCardRepository;
+import com.acquirex.repository.ApprovalRequestRepository;
+import com.acquirex.service.ApprovalService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.math.BigDecimal;
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+class ApprovalServiceTest {
+
+    @Mock
+    private ApprovalRequestRepository approvalRequestRepository;
+
+    @Mock
+    private AcquisitionCardRepository acquisitionCardRepository;
+
+    private ApprovalService approvalService;
+    private ApprovalRequestDto validRequestDto;
+    private AcquisitionCard testCard;
+    private ApprovalRequest testRequest;
+
+    @BeforeEach
+    void setUp() {
+        approvalService = new ApprovalService(approvalRequestRepository, acquisitionCardRepository);
+
+        validRequestDto = new ApprovalRequestDto();
+        validRequestDto.setCardNumber("1234567890123456");
+        validRequestDto.setCardCompanyCode("KB");
+        validRequestDto.setMerchantNumber("123456789012345");
+        validRequestDto.setAmount(new BigDecimal("50000.00"));
+        validRequestDto.setVat(new BigDecimal("5000.00"));
+
+        testCard = new AcquisitionCard();
+        testCard.setId(1L);
+        testCard.setCardNumber("1234567890123456");
+        testCard.setCardCompanyCode("KB");
+        testCard.setMerchantNumber("123456789012345");
+        testCard.setStatus(AcquisitionCard.CardStatus.PENDING);
+
+        testRequest = new ApprovalRequest();
+        testRequest.setId(1L);
+        testRequest.setCardId(1L);
+        testRequest.setTransactionId("TX12345678");
+        testRequest.setAmount(new BigDecimal("50000.00"));
+        testRequest.setVat(new BigDecimal("5000.00"));
+        testRequest.setApprovalStatus(ApprovalRequest.ApprovalStatus.REQUESTED);
+    }
+
+    @Test
+    @DisplayName("매입 승인 요청 성공 - 기존 카드")
+    void requestApproval_WithExistingCard_Success() {
+        when(acquisitionCardRepository.findByCardNumberAndCardCompanyCode(any(), any()))
+                .thenReturn(Optional.of(testCard));
+        when(approvalRequestRepository.save(any(ApprovalRequest.class))).thenReturn(testRequest);
+
+        ApprovalResponseDto response = approvalService.requestApproval(validRequestDto);
+
+        assertNotNull(response);
+        assertEquals("TX12345678", response.getTransactionId());
+        assertEquals("REQUESTED", response.getStatus());
+        verify(acquisitionCardRepository, never()).save(any());
+        verify(approvalRequestRepository, times(1)).save(any());
+    }
+
+    @Test
+    @DisplayName("매입 승인 요청 성공 - 신규 카드")
+    void requestApproval_WithNewCard_Success() {
+        when(acquisitionCardRepository.findByCardNumberAndCardCompanyCode(any(), any()))
+                .thenReturn(Optional.empty());
+        when(acquisitionCardRepository.save(any(AcquisitionCard.class))).thenReturn(testCard);
+        when(approvalRequestRepository.save(any(ApprovalRequest.class))).thenReturn(testRequest);
+
+        ApprovalResponseDto response = approvalService.requestApproval(validRequestDto);
+
+        assertNotNull(response);
+        assertEquals("REQUESTED", response.getStatus());
+        verify(acquisitionCardRepository, times(1)).save(any());
+    }
+
+    @Test
+    @DisplayName("매입 승인 처리 성공")
+    void approveRequest_Success() {
+        when(approvalRequestRepository.findById(1L)).thenReturn(Optional.of(testRequest));
+        when(approvalRequestRepository.save(any(ApprovalRequest.class)))
+                .thenAnswer(invocation -> invocation.getArgument(0));
+
+        ApprovalResponseDto response = approvalService.approveRequest(1L);
+
+        assertNotNull(response);
+        assertEquals("APPROVED", response.getStatus());
+        assertNotNull(response.getApprovalNumber());
+        assertNotNull(response.getApprovedAt());
+    }
+
+    @Test
+    @DisplayName("매입 승인 처리 실패 - 요청 없음")
+    void approveRequest_NotFound() {
+        when(approvalRequestRepository.findById(999L)).thenReturn(Optional.empty());
+        assertThrows(IllegalArgumentException.class, () -> approvalService.approveRequest(999L));
+    }
+
+    @Test
+    @DisplayName("매입 승인 처리 실패 - 이미 처리됨")
+    void approveRequest_AlreadyProcessed() {
+        testRequest.setApprovalStatus(ApprovalRequest.ApprovalStatus.APPROVED);
+        when(approvalRequestRepository.findById(1L)).thenReturn(Optional.of(testRequest));
+        assertThrows(IllegalStateException.class, () -> approvalService.approveRequest(1L));
+    }
+
+    @Test
+    @DisplayName("매입 승인 거절 성공")
+    void rejectRequest_Success() {
+        when(approvalRequestRepository.findById(1L)).thenReturn(Optional.of(testRequest));
+        when(approvalRequestRepository.save(any(ApprovalRequest.class)))
+                .thenAnswer(invocation -> invocation.getArgument(0));
+
+        ApprovalResponseDto response = approvalService.rejectRequest(1L, "한도 초과");
+
+        assertNotNull(response);
+        assertEquals("REJECTED", response.getStatus());
+    }
+
+    @Test
+    @DisplayName("승인 상태 조회 성공")
+    void getApprovalStatus_Success() {
+        when(approvalRequestRepository.findById(1L)).thenReturn(Optional.of(testRequest));
+
+        ApprovalResponseDto response = approvalService.getApprovalStatus(1L);
+
+        assertNotNull(response);
+        assertEquals(1L, response.getApprovalId());
+        assertEquals("TX12345678", response.getTransactionId());
+    }
+}
\ No newline at end of file