I would to know how to go to Jiuzhai Tiantang from Chengdu? which bus station that I can take ?

Well, you are suggested to take a bus from Chadianzi Bus Station to Jiuzhaigou, which takes about 8 hours and CNY157. Notice you should get off at Ganhaizi, and you need to tell the driver that you want to Jiuzhai Tiantang in advance. After that, you need to take a local car there.