It’s extremely important to get a visa before you come to (Mainland) China. The best option is obtaining a 10-year multiple entry visa. It will give you the flexibility to not only visit China when you want (for 60 days), but if you would like to fly to China and then fly or take the train to another city after a few days you wont run into any issues. 

Mainland:

Beijing
Shanghai

Pearl River Delta:

Guangzhou
Shenzhen

Special Administrative Regions (SAR):

Hong Kong
Macau