How can I travel in beijing, shanghai, xian and zhejiang in 7-9 days?

First of all, Zhejiang is a province, so you must have a destination city to go, say Hangzhou or others.

Anyway, for all ur destinations, here is my suggestion:
Take high-speed train from BJ to Shanghai. Then also use such trains to cities in Zhejiang. After that, fly from the city of Zhejiang Province or Shanghai city to Xian.

If you need any tour package, I suggest you use the service of TravelChinaGuide. Here is their email address for your convenience: travelchinaguide.com|tours
Hope help!