can iknow of some of following question: how can i get to SHANGHAI, Nanjing, Wuxi from Yancheng??

You can find buses for all the places in the local Coach Station.

Thanks Paul!! really appreciated,
how about return, can i get the ticket at the place i alight,,?

Hi, gegerally yes. Anyway, for convenience, here is the bus station for each city for your back journey:
Shanghai South Long-distance Bus
Nanjing South Passenger Transport Station
Wuxi Bus/Coach Station

For the ticket fare for these journeys. Here goes:
From Yancheng to Shanghai, Nanjing and Wuxi, the bus fare is CNY120, CNY93 and CNY88 respectively.