What documents I need to submit to renew my tourist visa?

You can't renew your tourist visa, once a visa expired, you have to apply for a new visa, just prepare all documents again and submit application. Have you used the tourist visa to enter Mainland China last year? If you do so, you don't need to submit the documents required for first time applicants, such as NBI, bank certificate, etc. The tourist visa sticker with entry record of China on your passport is very helpful for your new application.