It's not necessary to obtain Chinese currency prior to your departure as money can be easily exchanged at hotels, banks and major shops. The exchange rate at hotels are equivalent to banks, so there's no need to locate a bank. The fee is also very minimal (1% or less).
All currency exchange transactions require your passport as photo ID and don't forget to keep the receipt of each transaction for your records. The best form of currency to bring is cash in US Dollars because it's very difficult to exchange traveler's checks in China due to repetitive fraudulent activity.
It's important that the bills be fairly new, meaning free of writing or torn edges and that they are the large-faced bills (except for $1 bills since they are not printed in the large-face format yet).
There are ATM machines in China, however, it's unknown which Chinese banks work with which U.S. bank systems. If you match the logos on the back of your card to the logos on the ATM machine, it should work when you enter the PIN number linked to that card (whether it be an ATM or credit card).
For large purchases, we highly recommend paying with a credit card. In case you have a dispute with quality and/or pricing, you can always have the credit card company intervene or even stop payment, if necessary.
Please contact your bank and credit card companies before traveling to inform them of your destination.
Currently, one U.S. Dollar equals approximately 6.5 Yuan.
Renminbi (RMB) is the official currency of China (PRC). The primary unit of renminbi is yuan (¥). The current renminbi comes in a coin (1¥) and banknotes come in five different denominations (5¥, 10¥, 20¥, 50¥ and 100¥).
The shape of the banknotes are not uniform as in the United States. As the denomination of the bill increases, so will the size of the bill will slightly increase (5mm increments).

1¥ Coin

5¥ Banknote

10¥ Banknote

20¥ Banknote

50¥ Banknote

100¥ Banknote