Beijing is imposing new Internet regulations the government says are designed to tackle online pornography.
The new rules will allow China to cut off Internet services to sites that have not registered their domain name with the Ministry of Industry and Information Technology.
It is not clear whether the rules will apply to overseas Web sites.
China strictly censors the Internet and already blacklists and blocks many Web sites that authorities consider unacceptable, like the Tiananmen Square democracy protests of 1989.
Some free media advocates are concerned the new Internet regulations could be used to create a kind of "white list" of acceptable Web sites not related to pornography.
The government says it launched its campaign against Internet porn to purify the social environment and protect the mental health of minors.
Chinese state media say the crackdown has led to the detention of 3,500 people, the closure of nearly 7,000 Web sites and the removal of more than a million online items with lewd content.
Some information for this report was provided by AFP and Reuters.