How often do this buses run from chengdu to leshan? And to come back?

From CD to Leshan, the schedules of this bus station are from 06:45 to 19:30 with the frequency of around 30 mins. The ticket fare is about CNY 45 per person.
About the return way, take bus at Leshan Central Bus Station. The buses depart from 06:50 to 19:20 at intervals of around 40 mins. It also costs CNY 45 per person.
In addition, do you refer to the coach from CD to Research Base of Giant Panda? If yes, you don't need to take a coach. The distance between these two places is about 11 miles (18km). Just take a taxi. The cab fare would be CNY 40-50.