change for B1/B2 status to F-1 application is very strick. If you applied for a school or got the I-20 within 45 days after you enetred US with B1 or B2 visa, your change of status from B1/B2 to F-1 probably will be denied. Further, the US Immigration Service may deny an application to change status to F-1 if you "file" it within 60 days of your entry as a tourist. Also, even if you do it sucessfully, you might have a problem to get the F-1 visa in China when you visit China later because the US Conlsulate does not like people to get the B1/B2 visa and then, change their status to another status after entering US.
So, you may just go to China to get the F-1 visa to come back.
