Use child tags to set ComboBox data provider to ArrayCollection object
<?xml version="1.0"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:ComboBox> <mx:dataProvider> <mx:ArrayCollection> <mx:String>A</mx:String> <mx:String>B</mx:String> <mx:String>C</mx:String> </mx:ArrayCollection> </mx:dataProvider> </mx:ComboBox> </mx:Application>