在view端：

<?phpecho$form->labelEx($model,'test');?><?phpechoCHtml::dropDownList('province','',array('province',1=>'广东',2=>'广西'),array('ajax'=>array('type'=>'POST','url'=>Yii::app()->createUrl('site/getcity'),'update'=>'#city','data'=>array('province'=>'js:$("#province").val()'),)));?><?phpechoCHtml::dropDownList('city','',array('city'));?>

在controller端

publicfunctionactionGetcity(){if(!Yii::app()->request->isAjaxRequest)thrownewCHttpException(404);$province=(int)$_POST['province'];$data=array(1=>array(1=>'广州','深圳','东莞','佛山'),2=>array(1=>'桂林','南宁','玉林'));if(isset($data[$province])){foreach($data[$province]as$value=>$name){echoCHtml::tag('option',array('value'=>$value),CHtml::encode($name),true);}}else{echoCHtml::tag('option',array('value'=>''),'city',true);}}