If I reached shanghai at 20.00 p.m. how can I travel from shanghai to yangzhou.

Well, according to your arrival time, there is no direct long-distance bus that can take you to the destination. Also it's not easy for you to find a taxi or hire a private car at night. And the fare will be expensive.

So you are suggested to stay in a hotel in Shanghai overnight and start off in the next morning. There are several direct long-distance buses at General Bus Station. The schedules are from 07:00 to 17:30 with the interval of 40 to 50 mins. It costs CNY 93 per person.

Thankyou so much kina...