I will like to go Zhangjiajie on13th February 2014. By air or by train better?

Where do you start your journey?
If you start from Changsha, it is suggested to take a bus from Changsha South Bus Station to ZJJ directly. It is not necessary to book the bus tickets in advance.
If you start from other places such as Guangzhou, Shanghai and Beijing, you can choose to fly to reach there directly.
Or you may choose the trains, but the train take about 12 to around 20 hours. For the detail train schedules and prices, it is suggested to search on this website.