Although China's economy is rapidly changing it is still primarily based on cash transactions, but you do not need to bring Chinese currency with you. (Chinese currency is called Renminbi, or RMB, and the most common unit is the yuan. Hong Kong has its own currency, the Hong Kong Dollar.) The exchange rate for RMB in the U.S. is poor and you can easily change money in China at more favorable rates than at home.
The official exchange rate is about 8.2 yuan to one U.S. dollar. This rate is stable but to be safe check it before you travel. You can do this at your local bank, on-line by searching under the keywords "currency converter".
Traveler's checks are by far your best choice for travel expenses inside China not covered by your adoption package. You can exchange traveler's checks for local currency at hotels, airports, or banks. The rates all are about the same. Hotels post a slightly lower exchange than banks but are far more convenient, and although the bank rate is slightly higher, they charge an exchange fee, which hotels do not. In addition, traveler's checks can be replaced in China if they are lost or stolen (try that with cash).
You can use credit cards at your hotels in China to pay expenses not included in your adoption package such as laundry service, meals, or phone use charged to your room. The ability to use credit cards for shopping is increasing but is still limited. You should not rely on them for everyday purchases outside of your hotel.
U.S. dollars are of limited use inside China and each bill must be in excellent-to-mint condition to be exchanged. Vendors and banks will reject bills that are torn, smudged, dirty, visibly worn, or in any way defaced.
ATMs are also limited in availability, may not work, and only issue Chinese currency. Additionally, interest charges on cash advances are high and usually accrue immediately.
Personal checks have recently been introduced in China but their use is extremely rare. Vendors will not accept personal checks for purchases or currency exchange.
