Section Five of the Computer Information Network and Internet Security, Protection, and Management Regulations approved by the State Council on 11 December 1997 states the following:
No unit or individual may use the Internet to create, replicate, retrieve, or transmit the following kinds of information:
1. Inciting to resist or breaking the Constitution or laws or the implementation of administrative regulations;
2. Inciting to overthrow the government or the socialist system;
3. Inciting division of the country, harming national unification;
4. Inciting hatred or discrimination among nationalities or harming the unity of the nationalities;
5. Making falsehoods or distorting the truth, spreading rumors, destroying the order of society;
6. Promoting feudal superstitions, sexually suggestive material, gambling, violence, murder;
7. Terrorism or inciting others to criminal activity; openly insulting other people or distorting the truth to slander people;
8. Injuring the reputation of state organs;
9. Other activities against the Constitution, laws or administrative regulations.
I do not know if using alternative means of internet routing like Tor is illegal in and of itself. But I would not be surprised if it is.