diff --git a/demo/documentation/components/inputNumber/enUS/event.md b/demo/documentation/components/inputNumber/enUS/event.md
index 3c4b367c8..03c8294e2 100644
--- a/demo/documentation/components/inputNumber/enUS/event.md
+++ b/demo/documentation/components/inputNumber/enUS/event.md
@@ -3,6 +3,7 @@
 <n-input-number
   v-model="value"
   @change="handleChange"
+  @blur="handleBlur"
 />
 ```
 ```js
@@ -15,7 +16,10 @@ export default {
   methods: {
     handleChange (newValue) {
       this.$NMessage.info(`value: ${newValue}`)
-    }
+    },
+    handleBlur (e, v) {
+      this.$NMessage.info(`blur: ` + v)
+    },
   }
 }
 ```
diff --git a/demo/documentation/components/inputNumber/enUS/index.md b/demo/documentation/components/inputNumber/enUS/index.md
index 8364055c9..6b6885277 100644
--- a/demo/documentation/components/inputNumber/enUS/index.md
+++ b/demo/documentation/components/inputNumber/enUS/index.md
@@ -6,4 +6,5 @@ event
 min-max
 size
 step
+validator
 ```
\ No newline at end of file
diff --git a/demo/documentation/components/inputNumber/enUS/minMax.md b/demo/documentation/components/inputNumber/enUS/minMax.md
index d638ec69d..f94d0d7c4 100644
--- a/demo/documentation/components/inputNumber/enUS/minMax.md
+++ b/demo/documentation/components/inputNumber/enUS/minMax.md
@@ -15,7 +15,7 @@
 export default {
   data () {
     return {
-      value: 0
+      value: null
     }
   }
 }
diff --git a/demo/documentation/components/inputNumber/enUS/validator.md b/demo/documentation/components/inputNumber/enUS/validator.md
new file mode 100644
index 000000000..f58e9e56d
--- /dev/null
+++ b/demo/documentation/components/inputNumber/enUS/validator.md
@@ -0,0 +1,17 @@
+# Validator
+```html
+<n-input-number
+  v-model="value"
+  :validator="validator"
+/>
+```
+```js
+export default {
+  data () {
+    return {
+      value: null,
+      validator: x => x > 0
+    }
+  }
+}
+```
\ No newline at end of file
diff --git a/packages/common/InputNumber/src/main.vue b/packages/common/InputNumber/src/main.vue
index 906e66438..a2f735d3b 100644
--- a/packages/common/InputNumber/src/main.vue
+++ b/packages/common/InputNumber/src/main.vue
@@ -12,7 +12,7 @@
       type="button"
       class="n-input-number__minus-button"
       :class="{
-        [`n-input-number__minus-button--disabled`]: value !== null && safeMin !== null && value <= safeMin
+        [`n-input-number__minus-button--disabled`]: !minusable
       }"
       @mousedown="handleMouseDown"
       @click="minus"
@@ -25,8 +25,8 @@
       type="text"
       :value="value"
       :disabled="disabled ? 'disabled' : false"
+      @focus="handleFocus"
       @blur="handleBlur"
-      @input="handleInput"
       @keyup.enter="handleEnter"
     >
     <button
@@ -34,7 +34,7 @@
       type="button"
       class="n-input-number__add-button"
       :class="{
-        [`n-input-number__add-button--disabled`]: value !== null && safeMax !== null && value >= safeMax
+        [`n-input-number__add-button--disabled`]: !addable
       }"
       @mousedown="handleMouseDown"
       @click="add"
@@ -107,6 +107,10 @@ export default {
     disabled: {
       type: Boolean,
       default: false
+    },
+    validator: {
+      type: Function,
+      default: null
     }
   },
   computed: {
@@ -120,12 +124,29 @@ export default {
       if (parsedNumber !== null) return parsedNumber
       else return null
     },
+    minusable () {
+      if (this.validator) {
+        if (this.value !== null) return this.validator(this.value - this.step)
+        else return false
+      } else {
+        return !(this.value !== null && this.safeMin !== null && this.value <= this.safeMin)
+      }
+    },
+    addable () {
+      if (this.validator) {
+        if (this.value !== null) return this.validator(this.value + this.step)
+        else return false
+      } else {
+        return !(this.value !== null && this.safeMax !== null && this.value >= this.safeMax)
+      }
+    },
     safeMax () {
       const parsedNumber = parseNumber(this.max)
       if (parsedNumber !== null) return parsedNumber
       else return null
     },
     aValidValue () {
+      if (this.validator) return null
       if (this.safeMin !== null) {
         return Math.max(0, this.safeMin)
       } else if (this.safeMax !== null) {
@@ -137,29 +158,12 @@ export default {
   },
   watch: {
     value (newValue, oldValue) {
-      if (newValue !== null) {
-        if (this.safeMax !== null && newValue > this.safeMax) {
-          newValue = this.safeMax
-        }
-        if (this.safeMin !== null && newValue < this.safeMin) {
-          newValue = this.safeMin
-        }
-      }
-      this.$emit('change', newValue, oldValue)
-      this.formBlur('change', newValue)
-      /**
-       * newValue === oldValue won't trigger watcher!
-       * so the call stack won't fall in loop
-       */
-      this.$emit('input', newValue)
-    }
-  },
-  created () {
-    if (this.value !== null) {
-      if (this.safeMax !== null && this.value > this.safeMax) {
-        this.$emit('input', this.safeMax)
-      } else if (this.safeMin !== null && this.value < this.safeMin) {
-        this.$emit('input', this.safeMin)
+      const adjustedValue = this.adjustValue(newValue)
+      if (adjustedValue === newValue) {
+        this.$emit('change', newValue, oldValue)
+        this.formBlur('change', newValue)
+      } else {
+        this.$emit('input', adjustedValue)
       }
     }
   },
@@ -175,44 +179,62 @@ export default {
         this.dispatch('NFormItem', 'on-form-' + type, val)
       }
     },
+    handleFocus (e) {
+      this.$emit('focus', e, this.value)
+    },
     add () {
+      if (!this.addable) return
       if (this.value === null) {
         this.$emit('input', this.aValidValue)
       } else {
-        const valueAfterChange = this.value + this.safeStep
+        const valueAfterChange = this.adjustValue(this.value + this.safeStep)
         this.$emit('input', valueAfterChange)
       }
     },
     minus () {
+      console.log('minus', this.minusable)
+      if (!this.minusable) return
       if (this.value === null) {
         this.$emit('input', this.aValidValue)
       } else {
-        const valueAfterChange = this.value - this.safeStep
+        const valueAfterChange = this.adjustValue(this.value - this.safeStep)
         this.$emit('input', valueAfterChange)
       }
-    },
-    handleInput (e) {
-
     },
     handleEnter (e) {
-      this.$refs.input.blur()
+      const value = this.adjustValue(this.$refs.input.value)
+      this.$refs.input.value = value
+      this.$emit('input', value)
+    },
+    adjustValue (value) {
+      value = String(value).trim() || ''
+      if (value.trim() === '') {
+        value = null
+      } else if (Number.isNaN(Number(value))) {
+        value = this.value
+      } else {
+        value = Number(value)
+      }
+      if (value === null) {
+        return null
+      } if (this.validator) {
+        if (this.validator(value)) {
+          return value
+        } else {
+          return null
+        }
+      } else {
+        if (this.safeMin !== null && value < this.safeMin) value = this.safeMin
+        else if (this.safeMax !== null && value > this.safeMax) value = this.safeMax
+      }
+      return value
     },
     handleBlur (e) {
-      const value = e.target.value
-      if (value === '') {
-        this.$emit('input', null)
-        this.formBlur('blur', value)
-        return
-      }
-      const parsedNumber = Number(value)
-      if (Number.isNaN(parsedNumber)) {
-        e.target.value = String(this.value)
-      } else {
-        const valueAfterChange = parsedNumber
-        e.target.value = String(parsedNumber)
-        this.$emit('input', valueAfterChange)
-      }
-      this.formBlur('blur', parsedNumber)
+      const value = this.adjustValue(e.target.value)
+      e.target.value = value
+      this.$emit('input', value)
+      this.$emit('blur', e, value)
+      this.formBlur('blur', value)
     }
   }
 }
diff --git a/styles/InputNumber.scss b/styles/InputNumber.scss
index e32b50ebd..95426081b 100644
--- a/styles/InputNumber.scss
+++ b/styles/InputNumber.scss
@@ -25,7 +25,7 @@
       // background: map-get($--input-number-background-color, 'disabled');
       @include e(minus-button, add-button) {
         background: map-get($--input-number-button-background-color, 'disabled');
-        color: map-get($--input-number-button-text-color, 'disabled');
+        fill: map-get($--input-number-button-text-color, 'disabled');
         pointer-events: none;
       }
       @include e(input) {
@@ -61,11 +61,9 @@
       display: flex;
       align-items: center;
       justify-content: center;
-      path {
-        fill: map-get($--input-number-button-text-color, 'default');
-      }
+      fill: map-get($--input-number-button-text-color, 'default');
       font-size: 14px;
-      transition: color .3s $default-cubic-bezier, background-color .3s $default-cubic-bezier, box-shadow .3s $default-cubic-bezier;
+      transition: fill .3s $default-cubic-bezier, background-color .3s $default-cubic-bezier, box-shadow .3s $default-cubic-bezier;
       box-shadow: inset 0 0 0px 1px map-get($--input-number-border-color, 'default');
       &:hover ~ {
         @include e(border-layer) {
@@ -81,8 +79,9 @@
         background-color: map-get($--input-number-button-background-color, 'active')
       }
       @include m(disabled) {
+        cursor: not-allowed;
         background-color: map-get($--input-number-button-background-color, 'disabled');
-        color: map-get($--input-number-button-text-color, 'disabled');
+        fill: map-get($--input-number-button-text-color, 'disabled');
       }
     }
     @include e(minus-button) {