Set wordwrap to true
package { import flash.display.Sprite; import flash.text.TextField; public class Main extends Sprite { public function Main( ) { var field:TextField = new TextField( ); field.autoSize = flash.text.TextFieldAutoSize.LEFT; field.wordWrap = true; field.text = "AAA BBB CCC DDD AAA BBB CCC DDD AAA BBB CCC DDD AAA BBB CCC DDD"; addChild(field); } } }