The unit of Renminbi is a yuan and with smaller denominations called jiao and fen. The conversion among the three is: 1 yuan = 10 jiao =100 fen
RMB is issued both in notes and coins. The denominations of paper notes include 100, 50, 20, 10, 5, 2 and 1 yuan; 5, 2 and 1 jiao; and 5, 2 and 1 fen. The denominations of coins are 1 yuan; 5, 2 and 1 jiao; and 5, 2 and 1 fen.
In spoken Chinese, yuan is often called as kuai and the jiao as mao.
No foreign currency is allowed to circulate in China. Illegal selling of foreign exchange is not allowed. Travellers may exchange foreign currency cash or checks at Bank of China offices or exchange counters at the published exchange rates. These bureaus would issue a foreign exchange statement which shall be valid for 6 months.
The RMB is not easily convertible on the international market so it is only usable in China. It is advisable to change only the money that you need for you trip as it may be difficult to change back to you preferred currency. You can convert unused RMB to another currency in China by producing the receipts for your original purchase of RMB in China. This exchange is done at the airport as you leave China.