It will be the best to get the recommendation from your current advisor. But if you're very strong and can deeply impress the program that you will apply to, maybe it's fine. You may ask your previous advisor(s) in China to write letter(s) since generally at least 2 or 3 letters are required. I don't think it's a good idea to ask other facuty in your department to recommend. Who can guarantee they won't tell your boss and generally they wouldn't like to do it at all. Professors from other depart