how can u pre-book bus from Jiuzhaigou to chengdu? and how long is trip please?

Oh, generally speaking, it's not necessary for you to book the ticket in advance. There are always enough tickets in usual time. This journey takes 8 to 9 hours. The long-distance buses depart at 06:30, 07:00, 07:30, 07:50, 08:00, 08:20, 08:30, 08:50 and 09:30. The ticket fare is CNY 140 to 160 per person.

Anyway, here is the number of the official website for ticket booking: 4006608787. If you wish, have a try on it~

thanks for that, i was wondering about going from JZG to huanglong to chengdu by bus is this possible? i would prefer to do it on the way somehow even if its stopping over night there rather than go back and forth

At JZG, only one direct bus heads for Huanglong and it leaves at 07:00. To get back to Chengdu from Huanglong, there is no direct. You can choose to get back to JZG for a transfer or take a bus to Chuanzhusi first and then transfer to a direct bus to arrive. Well, usually people prefer to rent a car for a round trip between JZG and Huanglong. It is convenient and good for sightseeing.