By Deutsche Presse Agentur
Individuals and organisations cannot "damage national security, honour and interests" under the new legislation adopted by the National People's Congress Standing Committee.
Online attempts "to overthrow the socialist system, split the nation, undermine national unity, advocate terrorism and extremism" are all prohibited.
A Human Rights Watch (HRW) spokeswoman on Monday condemned the catch-all nature of the measures.
"Despite widespread international concern from corporations and rights advocates for more than a year, Chinese authorities pressed ahead with this restrictive law without making meaningful changes," said HRW China Director Sophie Richardson.
"The already heavily-censored internet in China needs more freedom, not less," Richardson said.
The law makes Internet companies into "de-facto agents of the state" according to Patrick Poon, China researcher at Amnesty International.
Business groups warned in August that the regulations will shut out foreign technology companies and that they include contentious requirements to store, censor and provide personal data to the authorities.
Zhao Zeliang, director general of the country's cyber security bureau, said at a press conference on Monday that the new internet security measures should not be seen as a barrier to trade.
"This is a misunderstanding, a bias," Zhao said, adding that the law was not designed to limit foreign technology and standards.