When in Rome, do as the Romans do. When you visit China you should have enough yuan -- China's official currency -- for daily expenses, rent, food, clothes and incidentals. Some people will say US dollars are accepted by businesses. But it won't be convenient for you to live your life depending on US dollars. You'll constantly be looking for somewhere to exchange your dollars for yuan. Except some hotels, resorts or places only for foreigners you can't use US dollars or other foreign currencies directly.  

You can exchange the currency over the counter at some banks in big cities like Beijing and Shanghai. Of course, you can use your credit cards in most of the shops but groceries (bought in grocery stores), rents or other bills will be collected in cash.

Retail branches and ATMs
 
Branches, sub-branches and ATMs are everywhere in Chinese cities especially downtown areas. You'll easily find them in the area you live. If you use bank cards you can deposit or withdraw cash in yuan everywhere and at anytime. Some charge a fee for the service.

You can get the addresses of the specific branches or ATMs of your favorite bank from their official Websites, Google local guidance or just by dialing the customer service hotline.
 
Money transfer
 
To transfer money from here to your home country is a technical job. You should seek help from law or accounting firms. Firstly you should follow Chinese laws. In some cases a foreigner needs to pay tax and service charges. It's better for you to make a plan with help from a lawyer or accountant on your money transfer plans. .

Click here for the official website of China's State Administration of Foreign Exchange which manages your money transfer from China to the designated location. 

(Shanghai Daily November 17, 2006)