diff --git a/src/main/java/side/onetime/controller/MemberController.java b/src/main/java/side/onetime/controller/MemberController.java
index 819763d..0901ad7 100644
--- a/src/main/java/side/onetime/controller/MemberController.java
+++ b/src/main/java/side/onetime/controller/MemberController.java
@@ -14,6 +14,15 @@
 public class MemberController {
     private final MemberService memberService;
 
+    // 멤버 등록 API
+    @PostMapping("/action-register")
+    public ResponseEntity<ApiResponse<MemberDto.RegisterMemberResponse>> registerMember(
+            @RequestBody MemberDto.RegisterMemberRequest registerMemberRequest) {
+
+        MemberDto.RegisterMemberResponse registerMemberResponse = memberService.registerMember(registerMemberRequest);
+        return ApiResponse.onSuccess(SuccessStatus._REGISTER_MEMBER, registerMemberResponse);
+    }
+
     // 멤버 로그인 API
     @PostMapping("/action-login")
     public ResponseEntity<ApiResponse<MemberDto.LoginMemberResponse>> loginMember(
diff --git a/src/main/java/side/onetime/dto/MemberDto.java b/src/main/java/side/onetime/dto/MemberDto.java
index 8a63086..8cf6145 100644
--- a/src/main/java/side/onetime/dto/MemberDto.java
+++ b/src/main/java/side/onetime/dto/MemberDto.java
@@ -10,6 +10,7 @@
 import side.onetime.domain.Event;
 import side.onetime.domain.Member;
 
+import java.util.List;
 import java.util.UUID;
 
 public class MemberDto {
@@ -19,10 +20,11 @@ public class MemberDto {
     @AllArgsConstructor
     @JsonNaming(value = PropertyNamingStrategies.SnakeCaseStrategy.class)
     @JsonInclude(JsonInclude.Include.NON_NULL)
-    public static class LoginMemberRequest {
+    public static class RegisterMemberRequest {
         private String eventId;
         private String name;
         private String pin;
+        private List<MemberDto.Schedule> schedules;
 
         public Member to(Event event) {
             return Member.builder()
@@ -34,6 +36,47 @@ public Member to(Event event) {
         }
     }
 
+    @Builder
+    @Getter
+    @NoArgsConstructor
+    @AllArgsConstructor
+    @JsonNaming(value = PropertyNamingStrategies.SnakeCaseStrategy.class)
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    public static class RegisterMemberResponse {
+        private String memberId;
+        private String category;
+
+        public static MemberDto.RegisterMemberResponse of(Member member, Event event) {
+            return RegisterMemberResponse.builder()
+                    .memberId(String.valueOf(member.getMemberId()))
+                    .category(event.getCategory().name())
+                    .build();
+        }
+    }
+
+    @Builder
+    @Getter
+    @NoArgsConstructor
+    @AllArgsConstructor
+    @JsonNaming(value = PropertyNamingStrategies.SnakeCaseStrategy.class)
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    public static class Schedule {
+        private String timePoint;
+        private List<String> times;
+    }
+
+    @Builder
+    @Getter
+    @NoArgsConstructor
+    @AllArgsConstructor
+    @JsonNaming(value = PropertyNamingStrategies.SnakeCaseStrategy.class)
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    public static class LoginMemberRequest {
+        private String eventId;
+        private String name;
+        private String pin;
+    }
+
     @Builder
     @Getter
     @NoArgsConstructor
diff --git a/src/main/java/side/onetime/exception/MemberErrorResult.java b/src/main/java/side/onetime/exception/MemberErrorResult.java
index d4c5936..711c226 100644
--- a/src/main/java/side/onetime/exception/MemberErrorResult.java
+++ b/src/main/java/side/onetime/exception/MemberErrorResult.java
@@ -11,6 +11,7 @@
 public enum MemberErrorResult implements BaseErrorCode {
     _NOT_FOUND_MEMBER(HttpStatus.NOT_FOUND, "404", "멤버를 찾을 수 없습니다."),
     _IS_EXISTED_NAME(HttpStatus.CONFLICT, "409", "이미 존재하는 이름입니다."),
+    _IS_ALREADY_REGISTERED(HttpStatus.CONFLICT, "409", "이미 등록된 멤버입니다."),
     _NOT_FOUND_MEMBERS(HttpStatus.NOT_FOUND, "404", "멤버 전체 목록을 가져오는 데 실패했습니다.")
     ;
 
diff --git a/src/main/java/side/onetime/global/common/constant/SuccessStatus.java b/src/main/java/side/onetime/global/common/constant/SuccessStatus.java
index b41377c..7802948 100644
--- a/src/main/java/side/onetime/global/common/constant/SuccessStatus.java
+++ b/src/main/java/side/onetime/global/common/constant/SuccessStatus.java
@@ -16,6 +16,7 @@ public enum SuccessStatus implements BaseCode {
     _CREATED_EVENT(HttpStatus.CREATED, "201", "이벤트 생성에 성공했습니다."),
     _GET_EVENT(HttpStatus.OK, "200", "이벤트 조회에 성공했습니다."),
     // Member
+    _REGISTER_MEMBER(HttpStatus.CREATED, "201", "멤버 등록에 성공했습니다."),
     _LOGIN_MEMBER(HttpStatus.OK, "200", "멤버 로그인에 성공했습니다."),
     _IS_POSSIBLE_NAME(HttpStatus.OK, "200", "멤버 이름 중복 확인에 성공했습니다."),
     // Schedule
diff --git a/src/main/java/side/onetime/repository/MemberRepository.java b/src/main/java/side/onetime/repository/MemberRepository.java
index 97915af..f473b55 100644
--- a/src/main/java/side/onetime/repository/MemberRepository.java
+++ b/src/main/java/side/onetime/repository/MemberRepository.java
@@ -11,7 +11,6 @@
 import java.util.UUID;
 
 public interface MemberRepository extends JpaRepository<Member, Long> {
-    Boolean existsByEventAndNameAndPin(Event event, String name, String pin);
     Boolean existsByEventAndName(Event event, String name);
     Optional<Member> findByEventAndNameAndPin(Event event, String name, String pin);
     Optional<Member> findByMemberId(UUID memberId);
diff --git a/src/main/java/side/onetime/service/MemberService.java b/src/main/java/side/onetime/service/MemberService.java
index f2bc8ed..0af5104 100644
--- a/src/main/java/side/onetime/service/MemberService.java
+++ b/src/main/java/side/onetime/service/MemberService.java
@@ -5,14 +5,18 @@
 import org.springframework.stereotype.Service;
 import side.onetime.domain.Event;
 import side.onetime.domain.Member;
+import side.onetime.domain.Schedule;
+import side.onetime.domain.Selection;
 import side.onetime.dto.MemberDto;
-import side.onetime.exception.EventErrorResult;
-import side.onetime.exception.EventException;
-import side.onetime.exception.MemberErrorResult;
-import side.onetime.exception.MemberException;
+import side.onetime.exception.*;
+import side.onetime.global.common.constant.Category;
 import side.onetime.repository.EventRepository;
 import side.onetime.repository.MemberRepository;
+import side.onetime.repository.ScheduleRepository;
+import side.onetime.repository.SelectionRepository;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.UUID;
 
 @Service
@@ -20,23 +24,85 @@
 public class MemberService {
     private final EventRepository eventRepository;
     private final MemberRepository memberRepository;
+    private final SelectionRepository selectionRepository;
+    private final ScheduleRepository scheduleRepository;
 
-    // 멤버 로그인 메서드
+    // 멤버 등록 메서드
     @Transactional
-    public MemberDto.LoginMemberResponse loginMember(MemberDto.LoginMemberRequest loginMemberRequest) {
-        UUID eventId = UUID.fromString(loginMemberRequest.getEventId());
+    public MemberDto.RegisterMemberResponse registerMember(MemberDto.RegisterMemberRequest registerMemberRequest) {
+        UUID eventId = UUID.fromString(registerMemberRequest.getEventId());
         Event event = eventRepository.findByEventId(eventId)
                 .orElseThrow(() -> new EventException(EventErrorResult._NOT_FOUND_EVENT));
 
-        // 이미 있는 유저인 경우 반환, 없을 경우 생성
-        Member member;
-        if (memberRepository.existsByEventAndNameAndPin(event, loginMemberRequest.getName(), loginMemberRequest.getPin())) {
-            member = memberRepository.findByEventAndNameAndPin(event, loginMemberRequest.getName(), loginMemberRequest.getPin())
-                    .orElseThrow(() -> new MemberException(MemberErrorResult._NOT_FOUND_MEMBER));
+        if (memberRepository.existsByEventAndName(event, registerMemberRequest.getName())) {
+            throw new MemberException(MemberErrorResult._IS_ALREADY_REGISTERED);
+        }
+
+        Member member = registerMemberRequest.to(event);
+        memberRepository.save(member);
+
+        List<Selection> selections;
+        if (event.getCategory().equals(Category.DAY)) {
+            selections = createMembersDaySelections(event, member, registerMemberRequest);
         } else {
-            member = loginMemberRequest.to(event);
-            memberRepository.save(member);
+            selections = createMembersDateSelections(event, member, registerMemberRequest);
+        }
+        selectionRepository.saveAll(selections);
+
+        return MemberDto.RegisterMemberResponse.of(member, event);
+    }
+
+    private List<Selection> createMembersDaySelections(Event event, Member member, MemberDto.RegisterMemberRequest registerMemberRequest) {
+        List<MemberDto.Schedule> schedules = registerMemberRequest.getSchedules();
+        List<Selection> selections = new ArrayList<>();
+        for (MemberDto.Schedule schedule : schedules) {
+            String day = schedule.getTimePoint();
+            List<String> times = schedule.getTimes();
+            List<Schedule> selectedSchedules = scheduleRepository.findAllByEventAndDay(event, day)
+                    .orElseThrow(() -> new ScheduleException(ScheduleErrorResult._NOT_FOUND_DAY_SCHEDULES));
+
+            for (Schedule selectedSchedule : selectedSchedules) {
+                if (times.contains(selectedSchedule.getTime())) {
+                    selections.add(Selection.builder()
+                            .member(member)
+                            .schedule(selectedSchedule)
+                            .build());
+                }
+            }
+        }
+        return selections;
+    }
+
+    private List<Selection> createMembersDateSelections(Event event, Member member, MemberDto.RegisterMemberRequest registerMemberRequest) {
+        List<MemberDto.Schedule> schedules = registerMemberRequest.getSchedules();
+        List<Selection> selections = new ArrayList<>();
+        for (MemberDto.Schedule schedule : schedules) {
+            String date = schedule.getTimePoint();
+            List<String> times = schedule.getTimes();
+            List<Schedule> selectedSchedules = scheduleRepository.findAllByEventAndDate(event, date)
+                    .orElseThrow(() -> new ScheduleException(ScheduleErrorResult._NOT_FOUND_DATE_SCHEDULES));
+
+            for (Schedule selectedSchedule : selectedSchedules) {
+                if (times.contains(selectedSchedule.getTime())) {
+                    selections.add(Selection.builder()
+                            .member(member)
+                            .schedule(selectedSchedule)
+                            .build());
+                }
+            }
         }
+        return selections;
+    }
+
+    // 멤버 로그인 메서드
+    public MemberDto.LoginMemberResponse loginMember(MemberDto.LoginMemberRequest loginMemberRequest) {
+        UUID eventId = UUID.fromString(loginMemberRequest.getEventId());
+        Event event = eventRepository.findByEventId(eventId)
+                .orElseThrow(() -> new EventException(EventErrorResult._NOT_FOUND_EVENT));
+
+        Member member = memberRepository.findByEventAndNameAndPin(event, loginMemberRequest.getName(), loginMemberRequest.getPin())
+                .orElseThrow(() -> new MemberException(MemberErrorResult._NOT_FOUND_MEMBER));
+
         return MemberDto.LoginMemberResponse.of(member, event);
     }