回複：question for H1 visa

You should be OK. I know someone had exactly the same visa path as yours and he didn't have any problem to get a return H1B visa from US Embassay in China in the past two years. So, I would not worry.

As for documents, just check out the US Embassay in China's website. It has all the information you would need for preparing documents.

Overall, comparing with a lot of other visas, H1B is much less troublesome as far as getting a return visa from China.