diff --git a/src/test/java/com/acquirex/approval/CardAcquisitionServiceTest.java b/src/test/java/com/acquirex/approval/CardAcquisitionServiceTest.java
new file mode 100644
index 0000000..b0098a5
--- /dev/null
+++ b/src/test/java/com/acquirex/approval/CardAcquisitionServiceTest.java
@@ -0,0 +1,102 @@
+package com.acquirex.approval;
+
+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.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.math.BigDecimal;
+import java.util.List;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+class CardAcquisitionServiceTest {
+
+    @Mock
+    private CardAcquisitionRepository repository;
+
+    @InjectMocks
+    private CardAcquisitionService service;
+
+    private CardAcquisition testAcquisition;
+
+    @BeforeEach
+    void setUp() {
+        testAcquisition = new CardAcquisition("1234567890123456", "MERCH001", new BigDecimal("100000"));
+        testAcquisition.setId(1L);
+    }
+
+    @Test
+    @DisplayName("유효한 정보로 매입 요청을 생성한다")
+    void shouldCreateAcquisitionWithValidData() {
+        when(repository.save(any(CardAcquisition.class))).thenReturn(testAcquisition);
+        CardAcquisition result = service.createAcquisition("1234567890123456", "MERCH001", new BigDecimal("100000"));
+        assertThat(result).isNotNull();
+        assertThat(result.getStatus()).isEqualTo(CardAcquisition.ApprovalStatus.PENDING);
+        verify(repository, times(1)).save(any(CardAcquisition.class));
+    }
+
+    @Test
+    @DisplayName("금액이 0 이하이면 예외를 발생시킨다")
+    void shouldThrowExceptionWhenAmountIsZeroOrNegative() {
+        assertThatThrownBy(() -> service.createAcquisition("1234567890123456", "MERCH001", BigDecimal.ZERO))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("0보다 커야 합니다");
+    }
+
+    @Test
+    @DisplayName("대기 상태의 매입 요청을 승인한다")
+    void shouldApprovePendingAcquisition() {
+        when(repository.findById(1L)).thenReturn(Optional.of(testAcquisition));
+        when(repository.save(any(CardAcquisition.class))).thenAnswer(i -> i.getArgument(0));
+        CardAcquisition result = service.approve(1L, "admin");
+        assertThat(result.getStatus()).isEqualTo(CardAcquisition.ApprovalStatus.APPROVED);
+        assertThat(result.getApprovedBy()).isEqualTo("admin");
+    }
+
+    @Test
+    @DisplayName("이미 승인된 요청은 다시 승인할 수 없다")
+    void shouldThrowExceptionWhenAlreadyApproved() {
+        testAcquisition.approve("previous");
+        when(repository.findById(1L)).thenReturn(Optional.of(testAcquisition));
+        assertThatThrownBy(() -> service.approve(1L, "admin"))
+                .isInstanceOf(IllegalStateException.class)
+                .hasMessageContaining("대기 상태");
+    }
+
+    @Test
+    @DisplayName("대기 상태의 매입 요청을 거절한다")
+    void shouldRejectPendingAcquisition() {
+        when(repository.findById(1L)).thenReturn(Optional.of(testAcquisition));
+        when(repository.save(any(CardAcquisition.class))).thenAnswer(i -> i.getArgument(0));
+        CardAcquisition result = service.reject(1L, "Invalid merchant");
+        assertThat(result.getStatus()).isEqualTo(CardAcquisition.ApprovalStatus.REJECTED);
+        assertThat(result.getRejectionReason()).isEqualTo("Invalid merchant");
+    }
+
+    @Test
+    @DisplayName("존재하지 않는 요청은 예외를 발생시킨다")
+    void shouldThrowExceptionWhenNotFound() {
+        when(repository.findById(999L)).thenReturn(Optional.empty());
+        assertThatThrownBy(() -> service.approve(999L, "admin"))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("찾을 수 없습니다");
+    }
+
+    @Test
+    @DisplayName("상태별 매입 요청을 조회한다")
+    void shouldFindByStatus() {
+        when(repository.findByStatus(CardAcquisition.ApprovalStatus.PENDING))
+                .thenReturn(List.of(testAcquisition));
+        List<CardAcquisition> result = service.findByStatus(CardAcquisition.ApprovalStatus.PENDING);
+        assertThat(result).hasSize(1);
+    }
+}