diff --git a/src/components/progress/nz-progress.component.ts b/src/components/progress/nz-progress.component.ts
index ab1d6dadc1..052205b9ff 100644
--- a/src/components/progress/nz-progress.component.ts
+++ b/src/components/progress/nz-progress.component.ts
@@ -87,7 +87,7 @@ export class NzProgressComponent implements ControlValueAccessor, OnInit {
   }
 
   writeValue(value: number): void {
-    this._percent = value;
+    this._percent = value == null ? 0 : +value;
     if (this._percent === 100) {
       this.nzStatus = 'success';
     } else {
diff --git a/src/showcase/nz-demo-progress/nz-demo-progress-basic.component.ts b/src/showcase/nz-demo-progress/nz-demo-progress-basic.component.ts
index bff6989961..9900a7b38d 100644
--- a/src/showcase/nz-demo-progress/nz-demo-progress-basic.component.ts
+++ b/src/showcase/nz-demo-progress/nz-demo-progress-basic.component.ts
@@ -3,6 +3,7 @@ import { Component } from '@angular/core';
 @Component({
   selector: 'nz-demo-progress-basic',
   template: `
+    <nz-progress [ngModel]="value"></nz-progress>
     <nz-progress [ngModel]="30"></nz-progress>
     <nz-progress [ngModel]="50" [nzStatus]="'active'"></nz-progress>
     <nz-progress [ngModel]="70" [nzStatus]="'exception'"></nz-progress>
@@ -11,4 +12,6 @@ import { Component } from '@angular/core';
   `,
   styles  : []
 })
-export class NzDemoProgressBasicComponent { }
+export class NzDemoProgressBasicComponent {
+  value: number;
+}