Where can I buy train tickets in Chengdu?

The official website is www.12306.cn

Ask your hotel where the closest reputable ticket office is or buy directly from the train station at least a day in advance. Tickets sell out quickly and in high season can be near impossible to get, unless you book well in advance. Please also be aware to leave ample time on the day of travel, as it may not be easy to navigate the train station.