diff --git a/npm/ng-packs/packages/identity/src/lib/components/users/users.component.html b/npm/ng-packs/packages/identity/src/lib/components/users/users.component.html
index 7873adf6ea..99d435c891 100644
--- a/npm/ng-packs/packages/identity/src/lib/components/users/users.component.html
+++ b/npm/ng-packs/packages/identity/src/lib/components/users/users.component.html
@@ -39,7 +39,7 @@
       ><div class="text-center"><i class="fa fa-pulse fa-spinner"></i></div
     ></ng-template>
 
-    <form *ngIf="form; else loaderRef" [formGroup]="form" (ngSubmit)="save()">
+    <form *ngIf="form; else loaderRef" [blueprints]="blueprints" [formGroup]="form" (ngSubmit)="save()">
       <ul ngbNav #nav="ngbNav" class="nav-tabs">
         <li ngbNavItem>
           <a ngbNavLink>{{ 'AbpIdentity::UserInformations' | abpLocalization }}</a>
diff --git a/npm/ng-packs/packages/identity/src/lib/components/users/users.component.ts b/npm/ng-packs/packages/identity/src/lib/components/users/users.component.ts
index 9fd6987d19..75065272f4 100644
--- a/npm/ng-packs/packages/identity/src/lib/components/users/users.component.ts
+++ b/npm/ng-packs/packages/identity/src/lib/components/users/users.component.ts
@@ -61,6 +61,9 @@ export class UsersComponent implements OnInit {
 
   entityDisplayName: string;
 
+  blueprints = { pattern: 'AbpIdentity::Volo.Abp.Identity:InvalidUserName[{{ actualValue }}]' };
+
+
   trackByFn: TrackByFunction<AbstractControl> = (index, item) => Object.keys(item)[0] || index;
 
   onVisiblePermissionChange = event => {
diff --git a/npm/ng-packs/packages/identity/src/lib/defaults/default-users-form-props.ts b/npm/ng-packs/packages/identity/src/lib/defaults/default-users-form-props.ts
index 370cb4c7ab..c61f83857c 100644
--- a/npm/ng-packs/packages/identity/src/lib/defaults/default-users-form-props.ts
+++ b/npm/ng-packs/packages/identity/src/lib/defaults/default-users-form-props.ts
@@ -3,13 +3,15 @@ import { getPasswordValidators } from '@abp/ng.theme.shared';
 import { ePropType, FormProp } from '@abp/ng.theme.shared/extensions';
 import { Validators } from '@angular/forms';
 
+const onlyLetterAndNumberRegex = /^[a-zA-Z0-9]+$/;
+
 export const DEFAULT_USERS_CREATE_FORM_PROPS = FormProp.createMany<IdentityUserDto>([
   {
     type: ePropType.String,
     name: 'userName',
     displayName: 'AbpIdentity::UserName',
     id: 'user-name',
-    validators: () => [Validators.required, Validators.maxLength(256)],
+    validators: () => [Validators.required, Validators.maxLength(256), Validators.pattern(onlyLetterAndNumberRegex)],
   },
   {
     type: ePropType.Password,