diff --git a/components/tree/interface.ts b/components/tree/interface.ts
index 1dc4d869f6..15ec82a6e0 100644
--- a/components/tree/interface.ts
+++ b/components/tree/interface.ts
@@ -15,16 +15,3 @@ export interface NzFormatBeforeDropEvent {
   node: NzTreeNode;
   pos: number;
 }
-
-export interface NzTreeNodeOptions {
-  title: string;
-  key: string;
-  isLeaf?: boolean;
-  checked?: boolean;
-  selected?: boolean;
-  selectable?: boolean;
-  disabled?: boolean;
-  disableCheckbox?: boolean;
-  expanded?: boolean;
-  children?: NzTreeNodeOptions[];
-}
diff --git a/components/tree/nz-tree-node.component.ts b/components/tree/nz-tree-node.component.ts
index 29eea85c38..44dc84fc65 100644
--- a/components/tree/nz-tree-node.component.ts
+++ b/components/tree/nz-tree-node.component.ts
@@ -92,7 +92,6 @@ import { NzTreeService } from './nz-tree.service';
                       [nzBeforeDrop]="nzBeforeDrop"
                       [nzCheckStrictly]="nzCheckStrictly"
                       [nzDefaultExpandAll]="nzDefaultExpandAll"
-                      [nzDefaultCheckedKeys]="nzDefaultCheckedKeys"
                       [nzDefaultExpandedKeys]="nzDefaultExpandedKeys"
                       [nzDefaultSelectedKeys]="nzDefaultSelectedKeys"
                       [nzTreeTemplate]="nzTreeTemplate"
@@ -132,7 +131,6 @@ export class NzTreeNodeComponent implements OnInit, AfterViewInit {
   dragPos = 2;
   prefixCls = 'ant-tree';
   _treeNode;
-  _checkStrictly;
   _expandAll = false;
   _defaultCheckedKeys = [];
   _defaultExpandedKeys = [];
@@ -155,7 +153,6 @@ export class NzTreeNodeComponent implements OnInit, AfterViewInit {
   @Input() nzCheckable: boolean;
   @Input() nzAsyncData;
   @Input() nzCheckStrictly: boolean;
-  @Input() nzDefaultCheckedKeys: string[];
   @Input() nzTreeTemplate: TemplateRef<void>;
   @Input() nzBeforeDrop: (confirm: NzFormatBeforeDropEvent) => Observable<boolean>;
 
@@ -389,8 +386,8 @@ export class NzTreeNodeComponent implements OnInit, AfterViewInit {
       node.isHalfChecked = false;
       this.nzTreeService.setCheckedNodeListStrict(this.nzTreeNode);
     } else {
-      this.nzTreeService.setCheckedNodeList(this.nzTreeNode);
       this.nzTreeService.checkTreeNode(node);
+      this.nzTreeService.setCheckedNodeList(this.nzTreeNode);
     }
     this.clickCheckBox.emit(this.nzTreeService.formatEvent('check', node, $event));
   }
diff --git a/components/tree/nz-tree-node.ts b/components/tree/nz-tree-node.ts
index 0d314fbb28..830acf9a6e 100644
--- a/components/tree/nz-tree-node.ts
+++ b/components/tree/nz-tree-node.ts
@@ -1,4 +1,15 @@
-import { NzTreeNodeOptions } from './interface';
+export interface NzTreeNodeOptions {
+  title: string;
+  key: string;
+  isLeaf?: boolean;
+  checked?: boolean;
+  selected?: boolean;
+  selectable?: boolean;
+  disabled?: boolean;
+  disableCheckbox?: boolean;
+  expanded?: boolean;
+  children?: NzTreeNodeOptions[];
+}
 
 export class NzTreeNode {
   title?: string;
diff --git a/components/tree/nz-tree.component.ts b/components/tree/nz-tree.component.ts
index 741a7345ec..9e91be6db9 100644
--- a/components/tree/nz-tree.component.ts
+++ b/components/tree/nz-tree.component.ts
@@ -25,7 +25,6 @@ import { NzTreeService } from './nz-tree.service';
                     [nzBeforeDrop]="nzBeforeDrop"
                     [nzCheckStrictly]="nzCheckStrictly"
                     [nzDefaultExpandAll]="nzDefaultExpandAll"
-                    [nzDefaultCheckedKeys]="nzDefaultCheckedKeys"
                     [nzDefaultExpandedKeys]="nzDefaultExpandedKeys"
                     [nzDefaultSelectedKeys]="nzDefaultSelectedKeys"
                     (clickCheckBox)="nzCheckBoxChange.emit($event)"
@@ -52,7 +51,6 @@ import { NzTreeService } from './nz-tree.service';
   ]
 })
 export class NzTreeComponent implements OnInit {
-  _root: NzTreeNode[] = [];
   _searchValue;
   _showLine = false;
   _prefixCls = 'ant-tree';
diff --git a/components/tree/nz-tree.spec.ts b/components/tree/nz-tree.spec.ts
index 3d209606ab..3bc630f8c6 100644
--- a/components/tree/nz-tree.spec.ts
+++ b/components/tree/nz-tree.spec.ts
@@ -116,6 +116,15 @@ describe('tree component test', () => {
       expect(treeElement.querySelectorAll('.ant-tree-checkbox-checked').length).toEqual(6);
       expect(checkSpy).toHaveBeenCalled();
       expect(checkSpy).toHaveBeenCalledTimes(1);
+      // for bug test https://github.com/NG-ZORRO/ng-zorro-antd/issues/1423
+      // auto merge child node
+      expect(treeInstance.treeComponent.getCheckedNodeList().length).toEqual(1);
+      expect(treeInstance.treeComponent.getCheckedNodeList()[0].title).toEqual('root1');
+      // cancel checked status
+      dispatchMouseEvent(targetNode, 'click');
+      fixture.detectChanges();
+      expect(treeElement.querySelectorAll('.ant-tree-checkbox-checked').length).toEqual(0);
+      expect(treeInstance.treeComponent.getCheckedNodeList().length).toEqual(0);
       // click toggle checked
       dispatchMouseEvent(targetNode, 'click');
       dispatchMouseEvent(targetNode, 'click');