i arrive at baiyun airport at 1.15 am on 30 nov 2012.

There is no bus or train running at that time from Guangzhou Baiyun Airport to Shenzhen. You may hire a cab, but it will be very expensive. I suggest you take the airport shuttle bus from Baiyun airport to Guangzhou downtown area and find a hotel to stay overnight. The next morning, you can go to Guangzhou East Railway Station to take bullet train to Shenzhen Railway Station. You hotel is nearby the train station.