diff --git a/apps/cs/src/entities/user/model/user-interface.ts b/apps/cs/src/entities/user/model/user-interface.ts
index abc48f9ae..dd250bd9e 100644
--- a/apps/cs/src/entities/user/model/user-interface.ts
+++ b/apps/cs/src/entities/user/model/user-interface.ts
@@ -20,6 +20,7 @@ export interface UserSearchParams extends PageableParams {
   grpId?: string;
   frDateYmd?: string;
   toDateYmd?: string;
+  userName?: string;
 }
 
 // 사용자 목록 응답 인터페이스
diff --git a/apps/cs/src/pages/groups/api/group-users-service.ts b/apps/cs/src/pages/groups/api/group-users-service.ts
index 2a11038e6..5af60a9ef 100644
--- a/apps/cs/src/pages/groups/api/group-users-service.ts
+++ b/apps/cs/src/pages/groups/api/group-users-service.ts
@@ -3,8 +3,9 @@ import { ENDPOINT } from "@/shared/config";
 import type {
   GroupUserService,
   GroupUserSearchParams,
-  GroupUserList,
+  GroupUserListResponseDto,
   GroupUserDetailResponse,
+  PageGroupUserList,
   GroupUserSaveData,
   GroupUserUpdateData,
 } from "../model/group-users-interface";
@@ -13,8 +14,8 @@ export class GroupUsersApiService implements GroupUserService {
   // 그룹 사용자 목록 조회
   public async findPageGroupUser(
     params: GroupUserSearchParams,
-  ): Promise<GroupUserList> {
-    const response = await client.get<GroupUserList>(
+  ): Promise<PageGroupUserList> {
+    const response = await client.get<PageGroupUserList>(
       `${ENDPOINT.CMS_SERVICE.GROUP_USERS}`,
       { params },
     );
@@ -34,9 +35,9 @@ export class GroupUsersApiService implements GroupUserService {
 
   // 그룹 사용자 저장
   public async saveGroupUser(
-    data: GroupUserSaveData,
-  ): Promise<GroupUserDetailResponse> {
-    const response = await client.post<GroupUserDetailResponse>(
+    data: GroupUserSaveData[],
+  ): Promise<GroupUserListResponseDto[]> {
+    const response = await client.post<GroupUserListResponseDto[]>(
       `${ENDPOINT.CMS_SERVICE.GROUP_USERS}`,
       data,
     );
diff --git a/apps/cs/src/pages/groups/model/group-users-interface.ts b/apps/cs/src/pages/groups/model/group-users-interface.ts
index 1587522a8..38daf6fe0 100644
--- a/apps/cs/src/pages/groups/model/group-users-interface.ts
+++ b/apps/cs/src/pages/groups/model/group-users-interface.ts
@@ -1,4 +1,4 @@
-import type { PageableParams } from "@/shared/model";
+import type { PageableList, PageableParams } from "@/shared/model";
 
 // 그룹 사용자 검색 파라미터 인터페이스
 export interface GroupUserSearchParams extends PageableParams {
@@ -7,49 +7,17 @@ export interface GroupUserSearchParams extends PageableParams {
 
 // 그룹 사용자 목록 응답 인터페이스
 export interface GroupUserListResponseDto {
-  grpSn: number;
+  mode: string;
+  groupId: string;
   userUnqId: string;
-  userId: string;
   userName: string;
-  email: string;
+  ogdpSeCd: string;
+  ogdpSeNm: string;
   mphn: string;
-  regDt: string;
-  rgtr: string;
-  mdfcnDt: string;
-  mdfr: string;
-  rgtrNm: string;
-  mdfrNm: string;
 }
 
 // 그룹 사용자 페이지 응답 인터페이스
-export interface GroupUserList {
-  content: GroupUserListResponseDto[];
-  pageable: {
-    sort: {
-      empty: boolean;
-      sorted: boolean;
-      unsorted: boolean;
-    };
-    offset: number;
-    pageSize: number;
-    pageNumber: number;
-    paged: boolean;
-    unpaged: boolean;
-  };
-  last: boolean;
-  totalPages: number;
-  totalElements: number;
-  size: number;
-  number: number;
-  sort: {
-    empty: boolean;
-    sorted: boolean;
-    unsorted: boolean;
-  };
-  first: boolean;
-  numberOfElements: number;
-  empty: boolean;
-}
+export type PageGroupUserList = PageableList<GroupUserListResponseDto>;
 
 // 그룹 사용자 상세 응답 인터페이스
 export interface GroupUserDetailResponse {
@@ -69,7 +37,8 @@ export interface GroupUserDetailResponse {
 
 // 그룹 사용자 저장 데이터 인터페이스
 export interface GroupUserSaveData {
-  grpSn: number;
+  mode: string;
+  groupId: string;
   userUnqId: string;
 }
 
@@ -81,7 +50,9 @@ export interface GroupUserUpdateData {
 // 그룹 사용자 서비스 인터페이스
 export interface GroupUserService {
   // 그룹 사용자 목록 조회
-  findPageGroupUser: (params: GroupUserSearchParams) => Promise<GroupUserList>;
+  findPageGroupUser: (
+    params: GroupUserSearchParams,
+  ) => Promise<PageGroupUserList>;
 
   // 그룹 사용자 단건 조회
   findByGroupAndUserId: (
@@ -90,7 +61,9 @@ export interface GroupUserService {
   ) => Promise<GroupUserDetailResponse>;
 
   // 그룹 사용자 저장
-  saveGroupUser: (data: GroupUserSaveData) => Promise<GroupUserDetailResponse>;
+  saveGroupUser: (
+    data: GroupUserSaveData[],
+  ) => Promise<GroupUserListResponseDto[]>;
 
   // 그룹 사용자 수정
   updateGroupUser: (
diff --git a/apps/cs/src/pages/groups/ui/additional-user-dialog.tsx b/apps/cs/src/pages/groups/ui/additional-user-dialog.tsx
new file mode 100644
index 000000000..e3a3ee7a1
--- /dev/null
+++ b/apps/cs/src/pages/groups/ui/additional-user-dialog.tsx
@@ -0,0 +1,192 @@
+"use client";
+
+import { useState } from "react";
+import {
+  keepPreviousData,
+  useQuery,
+  useQueryClient,
+} from "@tanstack/react-query";
+import {
+  getCoreRowModel,
+  useReactTable,
+  type PaginationState,
+  type RowSelectionState,
+  type ColumnDef,
+} from "@tanstack/react-table";
+import {
+  Button,
+  DataTable,
+  Dialog,
+  DialogContent,
+  DialogHeader,
+  DialogTitle,
+  DialogTrigger,
+  DialogFooter,
+  Input,
+  Checkbox,
+} from "@common/components";
+import {
+  UserApi,
+  type UserListResponse,
+  type UserSearchParams,
+} from "@/entities/user";
+import { ENDPOINT } from "@/shared/config";
+import { useAlertStore } from "@/shared/lib";
+import { GroupUsersApi } from "../api/group-users-service";
+
+type AdditionalUserDialogProps = {
+  groupId?: string;
+};
+
+function AdditionalUserDialog({ groupId }: AdditionalUserDialogProps) {
+  const queryClient = useQueryClient();
+  const alert = useAlertStore((state) => state.setMessage);
+
+  const [open, setOpen] = useState(false);
+  const [userSearchQuery, setUserSearchQuery] = useState<UserSearchParams>({
+    userName: "",
+  });
+  const [pagination, setPagination] = useState<PaginationState>({
+    pageIndex: 0,
+    pageSize: 10,
+  });
+  const [userRowSelection, setUserRowSelection] = useState<RowSelectionState>(
+    {},
+  );
+
+  const { data: usersList } = useQuery({
+    queryKey: [ENDPOINT.USER_SERVICE.USERS, userSearchQuery, pagination],
+    queryFn: () =>
+      UserApi.findPageUser({
+        ...userSearchQuery,
+        page: pagination.pageIndex,
+        size: pagination.pageSize,
+      }),
+    enabled: open,
+    placeholderData: keepPreviousData,
+  });
+
+  const userColumns: ColumnDef<UserListResponse>[] = [
+    {
+      id: "select",
+      header: ({ table }) => (
+        <Checkbox
+          checked={
+            table.getIsAllPageRowsSelected() ||
+            (table.getIsSomePageRowsSelected() && "indeterminate")
+          }
+          onCheckedChange={(value) => table.toggleAllPageRowsSelected(!!value)}
+          aria-label="전체 선택"
+        />
+      ),
+      cell: ({ row }) => (
+        <Checkbox
+          checked={row.getIsSelected()}
+          onCheckedChange={(value) => row.toggleSelected(!!value)}
+          aria-label="행 선택"
+        />
+      ),
+      enableSorting: false,
+      enableHiding: false,
+    },
+    {
+      accessorKey: "userId",
+      header: "사용자ID",
+    },
+    {
+      accessorKey: "userName",
+      header: "이름",
+    },
+    {
+      accessorKey: "ogdpSeNm",
+      header: "소속",
+    },
+    {
+      accessorKey: "mphn",
+      header: "연락처",
+    },
+  ];
+
+  const userTable = useReactTable({
+    data: usersList?.content ?? [],
+    columns: userColumns,
+    rowCount: usersList?.totalElements ?? 0,
+    state: { pagination, rowSelection: userRowSelection },
+    manualPagination: true,
+    enableRowSelection: true,
+    enableMultiRowSelection: true,
+    getCoreRowModel: getCoreRowModel(),
+    onPaginationChange: setPagination,
+    onRowSelectionChange: setUserRowSelection,
+    getRowId: (row) => row.userUnqId,
+  });
+
+  const handleAddUsers = async () => {
+    const selectedRows = Object.keys(userRowSelection);
+    if (selectedRows.length === 0 || !groupId) return;
+
+    try {
+      const usersToAdd = selectedRows.map((userUnqId) => ({
+        mode: "C",
+        groupId,
+        userUnqId,
+      }));
+
+      await GroupUsersApi.saveGroupUser(usersToAdd);
+      queryClient.invalidateQueries({
+        queryKey: [ENDPOINT.CMS_SERVICE.GROUP_USERS, groupId],
+      });
+      alert("사용자 추가를 완료했습니다.", () => {
+        setOpen(false);
+        setUserRowSelection({});
+      });
+    } catch (error) {
+      console.error(error);
+    }
+  };
+
+  const handleSearch = () => {
+    setPagination({ pageIndex: 0, pageSize: 10 });
+  };
+
+  return (
+    <Dialog open={open} onOpenChange={setOpen}>
+      <DialogTrigger asChild>
+        <Button disabled={!groupId}>사용자 추가</Button>
+      </DialogTrigger>
+      <DialogContent className="max-w-4xl">
+        <DialogHeader>
+          <DialogTitle>사용자 추가</DialogTitle>
+        </DialogHeader>
+        <div className="mb-4 flex items-end gap-2">
+          <Input
+            value={userSearchQuery.userName}
+            onChange={(e) =>
+              setUserSearchQuery({
+                ...userSearchQuery,
+                userName: e.target.value,
+              })
+            }
+            className="!text-[1.3rem]"
+            placeholder="사용자 이름으로 검색"
+          />
+          <Button onClick={handleSearch}>검색</Button>
+        </div>
+        <DataTable table={userTable} viewPagination />
+        <DialogFooter>
+          <Button color="white" onClick={() => setOpen(false)}>
+            취소
+          </Button>
+          <Button
+            onClick={handleAddUsers}
+            disabled={userTable.getSelectedRowModel().rows.length === 0}
+          >
+            추가
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
+
+export { AdditionalUserDialog };
diff --git a/apps/cs/src/pages/groups/ui/group-users-section.tsx b/apps/cs/src/pages/groups/ui/group-users-section.tsx
index 87b5ae7af..b736e3d13 100644
--- a/apps/cs/src/pages/groups/ui/group-users-section.tsx
+++ b/apps/cs/src/pages/groups/ui/group-users-section.tsx
@@ -1,7 +1,11 @@
 "use client";
 
 import { useState } from "react";
-import { keepPreviousData, useQuery } from "@tanstack/react-query";
+import {
+  keepPreviousData,
+  useQuery,
+  useQueryClient,
+} from "@tanstack/react-query";
 import {
   getCoreRowModel,
   useReactTable,
@@ -10,21 +14,26 @@ import {
 } from "@tanstack/react-table";
 import { Button, DataTable } from "@common/components";
 import { ENDPOINT } from "@/shared/config";
+import { useAlertStore } from "@/shared/lib";
 import { columns } from "../model/group-users-table-columns";
 import { GroupUsersApi } from "../api/group-users-service";
+import { AdditionalUserDialog } from "./additional-user-dialog";
 
 type GroupUsersSectionProps = {
   groupId?: string;
 };
 
 function GroupUsersSection({ groupId }: GroupUsersSectionProps) {
+  const queryClient = useQueryClient();
+  const alert = useAlertStore((state) => state.setMessage);
+
   const [pagination, setPagination] = useState<PaginationState>({
     pageIndex: 0,
     pageSize: 10,
   });
   const [rowSelection, setRowSelection] = useState<RowSelectionState>({});
 
-  const { data: groupUsersList, refetch } = useQuery({
+  const { data: groupUsersList } = useQuery({
     queryKey: [ENDPOINT.CMS_SERVICE.GROUP_USERS, groupId, pagination],
     queryFn: () =>
       GroupUsersApi.findPageGroupUser({
@@ -55,11 +64,19 @@ function GroupUsersSection({ groupId }: GroupUsersSectionProps) {
     if (selectedRows.length === 0 || !groupId) return;
 
     try {
-      for (const userUnqId of selectedRows) {
-        await GroupUsersApi.deleteGroupUser(groupId, userUnqId);
-      }
-      refetch();
-      setRowSelection({});
+      const usersToDelete = selectedRows.map((userUnqId) => ({
+        mode: "D",
+        groupId,
+        userUnqId,
+      }));
+
+      await GroupUsersApi.saveGroupUser(usersToDelete);
+      queryClient.invalidateQueries({
+        queryKey: [ENDPOINT.CMS_SERVICE.GROUP_USERS, groupId],
+      });
+      alert("사용자 삭제를 완료했습니다.", () => {
+        setRowSelection({});
+      });
     } catch (error) {
       console.error(error);
     }
@@ -71,7 +88,7 @@ function GroupUsersSection({ groupId }: GroupUsersSectionProps) {
         <div className="card-header">
           <h3 className="text-2xl font-medium text-label">그룹 사용자 목록</h3>
           <div className="flex gap-2">
-            <Button>등록</Button>
+            <AdditionalUserDialog groupId={groupId} />
             <Button
               color="red"
               disabled={table.getSelectedRowModel().rows.length === 0}
diff --git a/apps/cs/src/pages/groups/ui/index.ts b/apps/cs/src/pages/groups/ui/index.ts
deleted file mode 100644
index 3139984a1..000000000
--- a/apps/cs/src/pages/groups/ui/index.ts
+++ /dev/null
@@ -1 +0,0 @@
-export { GroupsPage } from "./groups-page";