Hongkong resident
Hongkong residents who have Chinese nationality can bring the effective reentry permit

Tourist from all over the world
Tourist should have visa when they come to china, and the validity time of passport should not be less than 6 months

Different place needs different visa. Tourist visa need general individual info while the working visa needs to show up the local invitation to proof that the person is employed by the local company

One can apply for visa at Chinese consulate or demand commission at Chinese tourism agent. The validity time for tourist visa is 30 days.

people from other place need certification if they want to visit the forbidden area. They can apply the certification at the enter-exit office. They need to apply visa when they travel to the Tibet Autonomy.