diff --git a/src/plugin/customParseFormat/index.js b/src/plugin/customParseFormat/index.js
index 034b5d5..cc338b0 100644
--- a/src/plugin/customParseFormat/index.js
+++ b/src/plugin/customParseFormat/index.js
@@ -7,8 +7,6 @@ const match2 = /\d\d/ // 00 - 99
 const match3 = /\d{3}/ // 000 - 999
 const match4 = /\d{4}/ // 0000 - 9999
 const match1to2 = /\d\d?/ // 0 - 99
-const matchUpperCaseAMPM = /[AP]M/
-const matchLowerCaseAMPM = /[ap]m/
 const matchSigned = /[+-]?\d+/ // -inf - inf
 const matchOffset = /[+-]\d\d:?\d\d/ // +00:00 -00:00 +0000 or -0000
 const matchWord = /\d*[^\s\d-:/()]+/ // Word
@@ -38,13 +36,28 @@ const getLocalePart = (name) => {
     part.indexOf ? part : part.s.concat(part.f)
   )
 }
-
+const meridiemMatch = (input, isLowerCase) => {
+  let isAfternoon
+  const { meridiem } = locale
+  if (!meridiem) {
+    isAfternoon = input === (isLowerCase ? 'pm' : 'PM')
+  } else {
+    for (let i = 1; i <= 24; i += 1) {
+      // todo: fix input === meridiem(i, 0, isLowerCase)
+      if (input.indexOf(meridiem(i, 0, isLowerCase)) > -1) {
+        isAfternoon = i > 12
+        break
+      }
+    }
+  }
+  return isAfternoon
+}
 const expressions = {
-  A: [matchUpperCaseAMPM, function (input) {
-    this.afternoon = input === 'PM'
+  A: [matchWord, function (input) {
+    this.afternoon = meridiemMatch(input, false)
   }],
-  a: [matchLowerCaseAMPM, function (input) {
-    this.afternoon = input === 'pm'
+  a: [matchWord, function (input) {
+    this.afternoon = meridiemMatch(input, true)
   }],
   S: [match1, function (input) {
     this.milliseconds = +input * 100
diff --git a/test/plugin/customParseFormat.test.js b/test/plugin/customParseFormat.test.js
index e1cf9e5..03b446a 100644
--- a/test/plugin/customParseFormat.test.js
+++ b/test/plugin/customParseFormat.test.js
@@ -1,11 +1,11 @@
 import MockDate from 'mockdate'
 import moment from 'moment'
 import dayjs from '../../src'
-import customParseFormat from '../../src/plugin/customParseFormat'
-import localizedFormats from '../../src/plugin/localizedFormat'
+import '../../src/locale/ru'
 import uk from '../../src/locale/uk'
 import '../../src/locale/zh-cn'
-import '../../src/locale/ru'
+import customParseFormat from '../../src/plugin/customParseFormat'
+import localizedFormats from '../../src/plugin/localizedFormat'
 
 dayjs.extend(customParseFormat)
 dayjs.extend(localizedFormats)
@@ -305,3 +305,18 @@ describe('Array format support', () => {
     expect(dayjs(input, format, 'zh-cn', true).format('YYYY MMMM DD')).toBe(input)
   })
 })
+
+describe('meridiem locale', () => {
+  const format = 'YYYY年M月D日Ah点mm分ss秒'
+  const format2 = 'YYYY-MM-DD HH:mm:ss'
+  it('AM', () => {
+    const input = '2018-05-02 01:02:03'
+    const date = dayjs(input).locale('zh-cn').format(format)
+    expect(dayjs(date, format, 'zh-cn').format(format2)).toBe(input)
+  })
+  it('PM', () => {
+    const input = '2018-05-02 20:02:03'
+    const date = dayjs(input).locale('zh-cn').format(format)
+    expect(dayjs(date, format, 'zh-cn').format(format2)).toBe(input)
+  })
+})