Can I upgrade my laptop(SONY Vaio)'s graphic card?

Upgrading the video card on your laptop is rarely a possibility because they are normally integrated (soldered) into the motherboard, you could either change the motherboard (basically a unknown personal) or they sell external picture cards (http://www.engadget.com/2007/01/02/asusteks-xg-station-brings-external-audio-video-processing-to/)