I found this on another website and it makes for some interesting reading:
Amid all the Protected content crackdown hubbub last summer, China passed a new immigration law that is set to take effect July 1. The Beijing Reviewer has put out a two-part blog series that highlights what you need to know about this law, including the possibility of fingerprinting requirements, changes in visa approval policies, and bigger fines and penalties for overstaying your visa.
For starters, here's what they have to say about visa renewal:
Discretion to Deny Visas: The statute appears to give officers unbridled discretion to refuse a visa if for any reason issuance is “not suitable.” Nor is the officer required to explain to the applicant the reason for the refusal. A closely related provision is that a person may be denied admission to China if the officer believes he or she may engage in activities inconsistent with the terms of the visa, such as working illegally or overstaying. This may be the basis for denying admission to a person who has violated the terms of his or her visa in the past.
The english transcript is on this link : Protected content
And there is an english blog summary as well : Protected content