Smoking has been banned in all indoor public spaces in Beijing.
The toughest crackdown to date aims to stem a looming health crisis.
But the move is controversial, with some saying that smoking should still be allowed in private restaurant rooms.
“Separate rooms are also with the indoor place,” pointed out Zhang Jianshu, Head of the Beijing Tobacco Control Association.
“The waiter and waitress have to serve you. They maybe harmed by your smoking. We have to protect the health rights and interests of all non-smokers.”
There are around 300 million smokers in China and cigarette sales reportedly went up by a third in 2014.
Lung cancer kills more 1.3 million people in the country each year, according to the World Health Organisation.
If caught, those flouting the new ban will be fined around 30 euros.
“I think it will be a little difficult. Some people have smoked for many years. It will be difficult to enforce this policy,” said Chu Tieling, a 23-year-old non-smoker and mother.
Smoking bans are already in force in other parts of China, although enforcement varies.
But officials hope the Beijing ban will encourage more smokers to stub out the habit.