Users who upload sex shows will be punished and websites that host them will also be held accountable, China's National Office Against Pornographic and Illegal Publications said in a statement.
Serious offenders will face criminal prosecution, state- run Xinhua news agency reported.
The office is tightening monitoring of major online video websites, and will suspend or shut down any that flout the law, it said.
Chinahas been cracking down hard on the internet pornography in recent years.
According to a report by the official China Internet Network Information Centre, China had nearly 668 million internet users by June, 2015, the highest in the world.