diff --git a/Group.js b/Group.js
index 461f70e2..5c08c48e 100644
--- a/Group.js
+++ b/Group.js
@@ -109,22 +109,6 @@ module.exports = class Group {
     const query = `?${qs.stringify(obj)}`
     return asyncRequest('get', `https://api.solapi.com/messages/v4/list${query}`, { headers: { Authorization: getAuth() } })
   }
-  /**
-   * 그룹에 추가된 메시지들을 예약 발송 요청합니다.
-   *
-   * @param {string} scheduledDate - yyyy-MM-dd HH:mm:ss 형식으로 된 문자열입니다. 해당 시각에 발송됩니다.
-   * @example
-   * // return promise object
-   * group.setScheduledDate('2019-10-10 10:10:10').then(body => {
-   *  console.log(body)
-   * })
-   */
-  setScheduledDate (scheduledDate) {
-    return asyncRequest('post', `https://api.solapi.com/messages/v4/groups/${this.getGroupId()}/schedule`, { headers: { Authorization: getAuth() }, form: { scheduledDate } })
-  }
-  cancelScheduled () {
-    return asyncRequest('delete', `https://api.solapi.com/messages/v4/groups/${this.getGroupId()}/schedule`, { headers: { Authorization: getAuth() } })
-  }
 
   /**
    * 그룹 삭제를 요청합니다.
diff --git a/README.md b/README.md
index 6b8ae01b..0ac7e688 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,6 @@ async function send (message, agent = {}) {
 
 [Group Message](https://github.com/solapi/solapi-sdk-js-v4/blob/develop/example/groupMessage.js), 
 [Simple Message](https://github.com/solapi/solapi-sdk-js-v4/blob/develop/example/simpleMessage.js),
-[Scheduled Messages](https://github.com/solapi/solapi-sdk-js-v4/blob/develop/example/scheduleMesssage.js),
 
 [more examples can be found at solapi-v4-examples](https://github.com/solapi/examples)
 ## Opening Issues
diff --git a/example/addScheduledDate.js b/example/addScheduledDate.js
deleted file mode 100644
index 3981a6e4..00000000
--- a/example/addScheduledDate.js
+++ /dev/null
@@ -1,23 +0,0 @@
-const moment = require('moment')
-const { config, Group } = require('../')
-config.init({
-  apiKey: 'ENTER API_KEY',
-  apiSecret: 'ENTER API_SECRET'
-})
-send({
-  text: 'Hello SOLAPI from Javascript',
-  type: 'SMS',
-  to: '수신번호',
-  from: '발신번호'
-})
-async function send (message) {
-  try {
-    const group = new Group()
-    await group.createGroup()
-    await group.addGroupMessage(message)
-    const scheduledDate = moment().add(1, 'days').toISOString()
-    await group.setScheduledDate(scheduledDate)
-  } catch (e) {
-    console.log(e)
-  }
-}
diff --git a/example/cancelScheduledDate.js b/example/cancelScheduledDate.js
deleted file mode 100644
index 609472f7..00000000
--- a/example/cancelScheduledDate.js
+++ /dev/null
@@ -1,24 +0,0 @@
-const moment = require('moment-timezone')
-const { config, Group } = require('../')
-config.init({
-  apiKey: 'ENTER API_KEY',
-  apiSecret: 'ENTER API_SECRET'
-})
-send({
-  text: 'Hello SOLAPI from Javascript',
-  type: 'SMS',
-  to: '수신번호',
-  from: '발신번호'
-})
-async function send (message) {
-  try {
-    const group = new Group()
-    await group.createGroup()
-    await group.addGroupMessage(message)
-    const scheduledDate = moment().tz('Asia/Seoul').add(1, 'days').format('YYYY-MM-DD H:m:s')
-    await group.setScheduledDate(scheduledDate)
-    await group.cancelScheduled()
-  } catch (e) {
-    console.log(e)
-  }
-}
diff --git a/example/scheduleMesssage.js b/example/scheduleMesssage.js
deleted file mode 100644
index bd93d991..00000000
--- a/example/scheduleMesssage.js
+++ /dev/null
@@ -1,21 +0,0 @@
-const moment = require('moment')
-const { config, Group } = require('../')
-config.init({
-  apiKey: 'ENTER API_KEY',
-  apiSecret: 'ENTER API_SECRET'
-})
-send()
-async function send (agent = {}, groupId = undefined) {
-  const group = new Group({ agent, groupId })
-  await group.createGroup() // groupId 가 없다면 필수로 작동 시켜야 됩니다.
-  console.log(group.getGroupId())
-  await group.addGroupMessage({
-    to: 'TO',
-    from: 'FROM',
-    text: 'MESSAGE',
-    type: 'SMS'
-  })
-  const date = moment(Date.now() + 60000).format('YYYY-MM-DD HH:mm:ss')
-  await group.setScheduledDate(date).catch(console.log)
-  await group.cancelScheduled().catch(console.log)
-}
diff --git a/tests/test.js b/tests/test.js
index e532d41b..8a7e4006 100644
--- a/tests/test.js
+++ b/tests/test.js
@@ -106,7 +106,7 @@ describe('test', () => {
       })
       expect(data.errorCount).to.equal(0)
       const result = await group.sendMessages()
-      expect(result).to.have.all.keys('app', 'balance', 'countForCharge', 'dateCompleted', 'dateSent', 'isRefunded', 'osPlatform', 'point', 'price', 'sdkVersion', 'count', 'log', 'status', '_id', 'groupId', 'accountId', 'apiVersion', 'dateCreated', 'dateUpdated', 'scheduledDate', 'flagUpdated')
+      expect(result).to.have.all.keys('app', 'balance', 'countForCharge', 'dateCompleted', 'dateSent', 'isRefunded', 'osPlatform', 'point', 'price', 'sdkVersion', 'count', 'log', 'status', '_id', 'groupId', 'accountId', 'apiVersion', 'dateCreated', 'dateUpdated', 'flagUpdated')
     })
     it('그룹 삭제 (정상)', async () => {
       const group = new Group()
@@ -127,7 +127,7 @@ describe('test', () => {
       const group = new Group()
       await group.createGroup()
       const data = await Group.getInfo(group.getGroupId())
-      expect(data).to.have.all.keys('app', 'balance', 'countForCharge', 'dateCompleted', 'dateSent', 'isRefunded', 'osPlatform', 'point', 'price', 'sdkVersion', 'count', 'log', 'status', '_id', 'groupId', 'accountId', 'apiVersion', 'dateCreated', 'dateUpdated', 'scheduledDate', 'flagUpdated')
+      expect(data).to.have.all.keys('app', 'balance', 'countForCharge', 'dateCompleted', 'dateSent', 'isRefunded', 'osPlatform', 'point', 'price', 'sdkVersion', 'count', 'log', 'status', '_id', 'groupId', 'accountId', 'apiVersion', 'dateCreated', 'dateUpdated', 'flagUpdated')
     })
     it('그룹 정보 조회 (생성 전)', async () => {
       const group = new Group()
@@ -143,36 +143,6 @@ describe('test', () => {
       const groupList = await Group.getMyGroupList()
       expect(groupList).to.have.all.keys('startKey', 'limit', 'groupList', 'nextKey')
     })
-    it('그룹 예약 (성공)', async () => {
-      const group = new Group()
-      tempGroup = group
-      await group.createGroup()
-      const data = await group.addGroupMessage({
-        to: getTo(),
-        from: getFrom(),
-        text: 'TEST',
-        type: 'SMS'
-      })
-      expect(data.errorCount).to.equal(0)
-      const date = new Date(Date.now() + (1000 * 60 * 60 * 10)).toISOString()
-      const result = await group.setScheduledDate(date)
-      expect(result).to.have.all.keys('app', 'balance', 'countForCharge', 'dateCompleted', 'dateSent', 'isRefunded', 'osPlatform', 'point', 'price', 'sdkVersion', 'count', 'log', 'status', '_id', 'groupId', 'accountId', 'apiVersion', 'dateCreated', 'dateUpdated', 'scheduledDate', 'flagUpdated')
-    })
-    it('그룹 예약 취소 (성공)', async () => {
-      const data = await tempGroup.cancelScheduled()
-      expect(data).to.have.all.keys('app', 'balance', 'countForCharge', 'dateCompleted', 'dateSent', 'isRefunded', 'osPlatform', 'point', 'price', 'sdkVersion', 'count', 'log', 'status', '_id', 'groupId', 'accountId', 'apiVersion', 'dateCreated', 'dateUpdated', 'scheduledDate', 'flagUpdated')
-    })
-    it('그룹 예약 (실패)', async () => {
-      const group = new Group()
-      await group.createGroup()
-      let data
-      try {
-        await group.setScheduledDate()
-      } catch (err) {
-        data = err
-      }
-      expect(data).to.have.all.keys('errorCode', 'errorMessage')
-    })
   })
   describe('message', () => {
     it('메시지 리스트 조회 (그룹 생성 전)', async () => {