Can I book online in advanced for long distance bus from Chengdu to Jiuzhaigou & vise versa?

I'm afraid it is not available to book the bus tickets online in advance, so you have to go to the Bus Station to buy on the spot.

Thanks for the reply and may I ask anoher question? Will there be a problem of availabilty for getting bus tickets a day before the intended departure (13 October 2013) from Chengdu to JZG and while at Chendu, can I then book return bus tickets from JZG back to Chengdu, a few days (5-6 days) in advance?

No, there will not problem to buy the ticket a day before to travel from Chengdu to JZG.

For the ticket of back journey, I heard you cannot get it in Chengdu city, but it is very easy to get at the Bus Station near the main entrance of JZG.

Thanks a million, u have been most helpful

Are you aware of the severe rain that has caused a landslide causing a blockage on the road from chengdu to the park. The road is open to private cars and taxis at the moment. I'm attempting to travel by bus from jzg to wenchuan and catch a bus there to chengdu