I hope you don't mind the English reply. I can't type in Chinese because my PC is not equipped with Chinese software.
Anyway, I am a Taiwanese student studying in Philadelphia.
To find info on accomodations in Philly, I recommend the following websites: http://www.apartments.com
Also try talking to the Taiwanese Student Association at the school you will be attending. Get the word out to other Taiwanese students that you are looking to sublet, and have them contact you if something becomes available.
Philadelphia is one of the largest city in the United States, and like every large city there are good and bad neighbourhoods. As long as you stay out of the rough part of town you will be fine. I don't know which school you will be attending, but in general, stay away from North Philadelphia; try to find an apartment in Center City, or if in University City, try not to go past 48th street.