diff --git a/src/index.js b/src/index.js
index 626be49a5..2c79674d7 100644
--- a/src/index.js
+++ b/src/index.js
@@ -92,10 +92,6 @@ class Dayjs {
     return !(this.$d.toString() === 'Invalid Date')
   }
 
-  isLeapYear() {
-    return ((this.$y % 4 === 0) && (this.$y % 100 !== 0)) || (this.$y % 400 === 0)
-  }
-
   $compare(that) {
     return this.valueOf() - dayjs(that).valueOf()
   }
diff --git a/test/query.test.js b/test/query.test.js
index 977a68e09..09f99b7f8 100644
--- a/test/query.test.js
+++ b/test/query.test.js
@@ -12,11 +12,6 @@ afterEach(() => {
 
 const testArr = [dayjs, moment]
 
-it('IsLeapYear', () => {
-  expect(dayjs('20000101').isLeapYear()).toBe(true)
-  expect(dayjs('2100-01-01').isLeapYear()).toBe(false)
-})
-
 describe('Is Before Is After Is Same', () => {
   it('Compare to dayjs object', () => {
     testArr.forEach((instance) => {