This is where it gets really tricky -- it is forbidden by law to wire the money out of China. One option is to withdrawal to cash, but you would then be smuggling the money out of the country by plane which presents a high risk that it could be confiscated. They have dogs that can sniff it out at the airports, as I`ve heard on this forum. Sounds bad.
Perhaps you could exchange the cash for precious gems and shove them up your ass when you leave the country. That might work, but good luck setting up the bank account and then converting the cash to precious commodities... I`ve been to China. Beijing mind you, and it was a clusterfuck to get anything done as a foreigner. They have no sense of queues or waiting for turns and as a Westerner you will likely be cheated if you don`t know exactly what you`re doing. Shanghai is probably a bit nicer in this regard though.
Edit: Better yet, you could send the money back to the US via a package? Still a bit risky, but probably safest and easiest option.
It seems that it's possible to take up to $10,000 out of China providing you have a licence. Taken from Yahoo Answers:
The Chinese customs are very strict regarding the export of currency, if you have legally earned the RMB during your stay in China, then be advised to follow the procedure hereinafter listed. The difference between the official and open market exchange rates is not tempting enough to risk illegal transaction, there is only a difference of a couple of maos but you will not get any official reciept to prove that you have exchanged your money legally.By the way Yao Bao Lu offers a better rate than Ya Show orf San Li Tun.
Under the rules of State Administration of Foreign Exchange, if you (a domestic resident or an overseas individual) carry foreign currency cash out of China more than the amount declared in last record of immigrating into China or there is no record of your foreign currency cash declared in your previous immigrating into China, and you want to bring a certain sum of foreign currency cash getting out of China, you must apply a Certificate of Carrying Foreign Currency and declare at Customs.
If you have foreign currency deposited in a Chinese bank, and you need to withdraw a certain amount of cash to get out of China, you may apply at the original Bank deposit office, the bank will issue Certificate of Carrying Foreign Currency according to the national regulation.
☆Operation Guide
1. You don’t need to apply the License for taking USD 5,000 (inclusive) or equivalent. Customs will let you go, except you travel across the boarder in one day or within a short period.
2. To apply for a Certificate of Carrying Foreign Currency for amount from USD 5,000 to USD 10,000 (inclusive) or equivalent, you should take ICBC deposit voucher, your passport or efficient visa. At departure, Customs will let you go by checking if Certificate of Carrying Foreign Currency sealed by the bank.
3. If over USD 10,000 or equivalent is need to be brought out of China, you need to apply the certificate at branches of State Administration of Foreign Exchange (hereinafter referred as SAFE) located at the same place of the bank deposit office or the bank branch where you deposit or purchase foreign currency. Customs will let you go by checking if the License is sealed by SAFE or not.
4. If multiple certificates are used and the cumulative sum of all certificates sealed by the bank is over USD 10,000 or equivalent, Customs will not let you go.
5. The Certificate is valid once within 30 days from the issue date.
