If you’re going to spend a decent amount of time in CHina, it probably makes sense to open a bank account there. You should open one if you plan on earning any money while over there, as it’s not the best idea to have cash stuffed in your pillow. Even if you have a foreign bank account, you won’t be able to deposit the yuan you earn in there as your account will be denominated in a different currency.
Fortunately for you opening a RMB denominated account is actually a straight forward process. You should only need your passport and yourself. If you have other supporting documentation like a local address, letter of employment and a Chinese friend, none of those would hurt your attempt.
You may be tempted to head to the local branch of a foreign bank. Most foreign banks now have branches in major Chinese cities, but most of them also have fairly substantial minimum balance requirements you will need to fulfill to avoid paying maintenance fees. If you pick a local bank, there are usually very low to no minimum balance requirements.
When you get to the bank, ask if someone speaks English. It may take an extra ten minutes to find that person who speaks English, but it’s worth your time to get this right the first time. You should also make sure you’re signing up for a checking account, and ask if you can get a debit card too. They are becoming more and more common in China in major cities. If you’re in the boonies it’s still almost totally cash.
As far as which bank you should choose, you have no shortage of options in CHina. Shanghai literally has more bank branches than any other city I’ve ever visited. Some of the biggies are Bank of China, ICBC, Construction Bank of China, Agricultural Bank of China, the list goes on and on.
One important thing you should know. If you are changing money from your local currency to Chinese RMB and depositing it, you’ll have very little trouble. If at any point you need to reconvert that currency to something else, all bets are off. Technically foreigners are allowed to convert 500 dollars per day, but must be present at a local branch and bring their passport. Even this requirement is spotty however. Some branches won’t let you do it at all, some don’t enforce any limits or ID requirements. It will be infinitely easier for you if you can bring a Chinese friend along. They don’t face the same restrictions you do as a foreigner and will probably be able to get the job done in a tenth the time.