I want to spend a little while in China, but I am unsure of what the laws/rules are to live in China for 5 to 6 months when you are a foreigner. Any advice?
Well it depends on where you are from, different countries can extend to different times. It also depends on where you are when you want to extend. I extended up to 3 months whilst staying in Shang hai. That was a relatively easy experience. Trying to do it before you go might be different however.
This might be helpful:
Good luck! over 6 years ago