diff --git a/backend/emm-sale/src/main/java/com/emmsale/member/application/MemberActivityCommandService.java b/backend/emm-sale/src/main/java/com/emmsale/member/application/MemberActivityCommandService.java
new file mode 100644
index 000000000..58816309b
--- /dev/null
+++ b/backend/emm-sale/src/main/java/com/emmsale/member/application/MemberActivityCommandService.java
@@ -0,0 +1,105 @@
+package com.emmsale.member.application;
+
+import static java.util.stream.Collectors.toUnmodifiableList;
+
+import com.emmsale.activity.domain.ActivityRepository;
+import com.emmsale.member.application.dto.MemberActivityAddRequest;
+import com.emmsale.member.application.dto.MemberActivityInitialRequest;
+import com.emmsale.member.application.dto.MemberActivityResponses;
+import com.emmsale.member.domain.Member;
+import com.emmsale.member.domain.MemberActivity;
+import com.emmsale.member.domain.MemberActivityRepository;
+import com.emmsale.member.exception.MemberException;
+import com.emmsale.member.exception.MemberExceptionType;
+import java.util.HashSet;
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@Transactional
+@RequiredArgsConstructor
+public class MemberActivityCommandService {
+
+  private final MemberActivityRepository memberActivityRepository;
+  private final ActivityRepository activityRepository;
+
+  public void registerActivities(
+      final Member member,
+      final MemberActivityInitialRequest memberActivityInitialRequest
+  ) {
+    if (member.isOnboarded()) {
+      throw new MemberException(MemberExceptionType.ALREADY_ONBOARDING);
+    }
+    final List<Long> activityIds = memberActivityInitialRequest.getActivityIds();
+    saveMemberActivities(member, activityIds);
+
+    member.updateName(memberActivityInitialRequest.getName());
+  }
+
+  private void saveMemberActivities(final Member member, final List<Long> activityIds) {
+    final List<MemberActivity> memberActivities = activityRepository.findAllById(activityIds)
+        .stream()
+        .map(it -> new MemberActivity(it, member))
+        .collect(toUnmodifiableList());
+
+    validateAllActivityIdsExist(activityIds, memberActivities);
+
+    memberActivityRepository.saveAll(memberActivities);
+  }
+
+  private void validateAllActivityIdsExist(
+      final List<Long> activityIds,
+      final List<MemberActivity> memberActivities
+  ) {
+    if (memberActivities.size() != activityIds.size()) {
+      throw new MemberException(MemberExceptionType.INVALID_ACTIVITY_IDS);
+    }
+  }
+
+  public List<MemberActivityResponses> addActivity(
+      final Member member,
+      final MemberActivityAddRequest memberActivityAddRequest
+  ) {
+    final List<Long> activityIds = memberActivityAddRequest.getActivityIds();
+    final List<MemberActivity> memberActivities = memberActivityRepository.findAllByMember(member);
+    if (hasDuplicateId(activityIds)) {
+      throw new MemberException(MemberExceptionType.DUPLICATE_ACTIVITY);
+    }
+    if (isAlreadyExistActivity(memberActivities, activityIds)) {
+      throw new MemberException(MemberExceptionType.ALREADY_EXIST_ACTIVITY);
+    }
+    saveMemberActivities(member, activityIds);
+
+    return MemberActivityResponses.from(memberActivityRepository.findAllByMember(member));
+  }
+
+  private boolean isAlreadyExistActivity(final List<MemberActivity> memberActivities,
+      final List<Long> activityIds) {
+    return memberActivities
+        .stream()
+        .anyMatch(memberActivity ->
+            activityIds.contains(memberActivity.getActivity().getId())
+        );
+  }
+
+  private boolean hasDuplicateId(final List<Long> activityIds) {
+    return new HashSet<>(activityIds).size() != activityIds.size();
+  }
+
+  public List<MemberActivityResponses> deleteActivity(
+      final Member member,
+      final List<Long> deleteActivityIds
+  ) {
+    final List<Long> savedMemberActivityIds =
+        memberActivityRepository.findAllByMemberAndActivityIds(member, deleteActivityIds)
+            .stream()
+            .map(MemberActivity::getId)
+            .collect(toUnmodifiableList());
+
+    memberActivityRepository.deleteAllByIdInBatch(savedMemberActivityIds);
+
+    return MemberActivityResponses.from(memberActivityRepository.findAllByMember(member));
+  }
+}
diff --git a/backend/emm-sale/src/main/java/com/emmsale/member/application/MemberActivityQueryService.java b/backend/emm-sale/src/main/java/com/emmsale/member/application/MemberActivityQueryService.java
new file mode 100644
index 000000000..f70313592
--- /dev/null
+++ b/backend/emm-sale/src/main/java/com/emmsale/member/application/MemberActivityQueryService.java
@@ -0,0 +1,24 @@
+package com.emmsale.member.application;
+
+import com.emmsale.member.application.dto.MemberActivityResponses;
+import com.emmsale.member.domain.Member;
+import com.emmsale.member.domain.MemberActivityRepository;
+import com.emmsale.member.domain.MemberRepository;
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@Transactional(readOnly = true)
+@RequiredArgsConstructor
+public class MemberActivityQueryService {
+
+  private final MemberRepository memberRepository;
+  private final MemberActivityRepository memberActivityRepository;
+
+  public List<MemberActivityResponses> findActivities(final Long memberId) {
+    final Member member = memberRepository.getByIdOrElseThrow(memberId);
+    return MemberActivityResponses.from(memberActivityRepository.findAllByMember(member));
+  }
+}
diff --git a/backend/emm-sale/src/test/java/com/emmsale/member/application/MemberActivityQueryServiceTest.java b/backend/emm-sale/src/test/java/com/emmsale/member/application/MemberActivityCommandServiceTest.java
similarity index 98%
rename from backend/emm-sale/src/test/java/com/emmsale/member/application/MemberActivityQueryServiceTest.java
rename to backend/emm-sale/src/test/java/com/emmsale/member/application/MemberActivityCommandServiceTest.java
index 99db4b09c..4730a665d 100644
--- a/backend/emm-sale/src/test/java/com/emmsale/member/application/MemberActivityQueryServiceTest.java
+++ b/backend/emm-sale/src/test/java/com/emmsale/member/application/MemberActivityCommandServiceTest.java
@@ -21,7 +21,7 @@
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 
-class MemberActivityQueryServiceTest extends ServiceIntegrationTestHelper {
+class MemberActivityCommandServiceTest extends ServiceIntegrationTestHelper {
 
   @Autowired
   private MemberActivityService memberActivityService;