Hello Linda
There is no limit on the amount of foreign currency you can take into China, but if you take more than £2,000 you will need to declare it on arrival. You may also take in 6,000 yuan (about £400).
Your best bet is to take travellers' cheques in US Dollars. Bear in mind that you'll probably only be able to change them for Chinese currency in branches of the Bank of China. Stick to travellers' cheques from well-known companies such as Thomas Cook or American Express.
Kind regards,
Olly, your editor