RMB (Renminbi) is the sole legitimate currency of the People's Republic of China. The basic unit of RMB is yuan, (pronounced in local dialest as kuai), which is divided into 10 jiao (pronounced as mao), which is again divided into 10 fen.
RMB paper notes include 1, 2, 5, 10, 50 and 100 yuan, and the smaller 1, 2 and 5 mao. There are also 1,2, 5 yuan, 1, 2, 5 mao and 1, 2, 5 fen coins.
Bureaux de change sponsored by the Bank of China are set up at Beijing International Airport, hotels and tourist stores. The exchange rate fluctuates with international market conditions. You should keep the form you fill in when changing money, because you will need to show it when you change RMB back into foreign currency.
Most bureaux de change open seven days a week from 9:00 to 17:00.