A core component of the law, passed by the standing committee of the National People's Congress (NPC), is to make all key network infrastructure and information systems "secure and controllable".
President Xi Jinping has said China's security covers areas including politics, culture, the military, the economy, technology and the environment.
Also Read
Zheng Shuna, vice chairwoman of the Legislative Affairs Commission of the NPC standing committee, downplayed those concerns, saying China welcomes "all countries' businesses to operate in China and provide legitimate services according to law".
"We will continue to follow the path of peaceful development but we absolutely will not give up our legitimate rights and absolutely will not sacrifice the country's core interests," she said at a briefing.
The security of territorial seas and airspace is among those core interests, which, according to the legislation, China will take "all necessary measures" to safeguard.
The law, which comes amid tensions with neighbours over disputes in the South China and East China Seas, passed through the NPC standing committee, the top body of China's rubber stamp parliament, by a vote of 154 to zero, with one abstention.
The national security law is part of a raft of government legislation - including laws on anti-terrorism, cyber security and foreign non-government organizations - that have drawn criticism from foreign governments, business and civil society groups.
Those policies, many of which have cyber security components, have emerged after former National Security Agency contractor Edward Snowden disclosed that US spy agencies planted code in American tech exports to snoop on overseas targets.
"The fact that these different pieces of legislation are all moving forward in tandem indicates the seriousness of Beijing's commitment as well as the growing influence of hardliners shaping China's technology policy agenda," Samm Sacks, an analyst at U.S.-based consulting firm Eurasia Group, said in an emailed statement.
Critics have argued that the extensive nature of the law, which covers everything from China's deep sea and space assets to "harmful cultural influences", constitutes national security overreach.
Its passage also coincides with a crackdown on dissent, as the government has detained and jailed activists and blamed "foreign forces" for the pro-democracy protests in Hong Kong last year.
Hong Kong and Macau must "fulfill responsibilities to safeguard national security" according to the law, which also covers crimes of subversion and inciting rebellion. That reference could spark more fears of Beijing encroaching on Hong Kong's rule of law.
Britain returned Hong Kong to China in 1997 under a "one country, two systems" formula, with the promise of a high degree of autonomy. Unlike on the mainland, Hong Kong does not have laws criminalizing subversion of the state. Macau, a former Portuguese colony, returned to China in 1999.
Some seven months after Hong Kong police forcibly cleared pro-democracy protesters from the streets, tens of thousands of people were expected to rally for free elections on Wednesday as the city marks the 18th anniversary of its return to China.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app