Public smoking in China's capital, Beijing, is now banned after the introduction of a new law.
China has over 300 million smokers and over a million Chinese people die from smoking-related illnesses every year.
Smoking bans already existed in China, but have largely failed to crack down on the habit.
These tougher regulations ban lighting up in restaurants, offices and on public transport in Beijing. Thousands of inspectors will enforce the rules.
'Name and shame'
The rules were vague, however, and often flouted by Chinese smokers who are accustomed to lighting up at will.
The new rules were agreed by lawmakers in November 2014 but only came into effect on 1 June.
Under the legislation lawbreakers in Beijing will be fined 200 yuan (£21; $32) and businesses that turn a blind eye could be fined up to 10,000 yuan.
Repeat offenders will be named and shamed on a government website, according to the Reuters news agency.
The new law also cracks down on tobacco advertising across the city.
The World Health Organization has welcomed the new tougher regulations.
"When implemented, this new law will permanently bring clean air to all of Beijing's indoor public places - in doing so, protecting Beijing's more than 20 million residents from the deadly effects of exposure to toxic second-hand smoke," said its representative in China, Dr Bernhard Schwartlander.
However, others believe that the sheer popularity of the habit will make the regulations difficult to enforce.
Yang Gonghuan, former vice-director of China's centre for disease control told the AFP news agency: "It is unrealistic to absolutely abolish 'indoor smoking' since too many people smoke."