ok I Got the Answer, I use SWFLoader Instead of VideoDisplay.Here the Code. Here I use Same Youtube URL.
private var url:String = "http://www.youtube.com/v/LqNQV3tsX1Y";
<mx:SWFLoader id="swfLoader"
minHeight="390"
minWidth="640"
source="{url}"
bottom="1"
left="1"
right="1"
top="1"
autoLoad="true"
maintainAspectRatio="true"
scaleContent="false"/>
Thanks...