thanks a lot!!
Some follow up question:
would it better for a company to file or I file as an individual?
-You need to file i-131 by yourself (you may ask your employer to pay the filing fee), but at the same time, the company may file N-470 for you, Application to Preserve Residence for Naturalization Purposes. Thus, if you want to apply for the US citizenship, your stay outside US will be counted as your physical presence in US, and your US cizenship application will not be affected. Talk to your employer/lawyer. See:
is the i-131 easy to be rejected?
-No. Just say you will work for your US employer temporarily in China.
if so, usual by what reason, and would it affect my next i-131 application?
greatly appreciate your help!!!
