Background and challenges to implementation:
On June 1^st, 2015, a remarkable 100% Smoke Free Law came into effect in Beijing. On January 1^st, 2017, Shenzhen became 100% smoke free city and on March 1^st, 2017 the Shanghai smoke free law came into effect. As a result, over 60 million population in China are now protected from second-hand smoke (SHS) exposure in public places, work places and public transportation.

Intervention or response:
Vital Strategies has collaborated with city governments, including Beijing, Shenzhen and Shanghai, to conduct evidence-based tobacco control mass media campaigns, incorporating message testing research to guide development of communication materials, integrated media planning utilizing a mix of media communication channels and undertaking evaluation surveys to measure campaign impact.
To support implementation of the Beijing 100% smoke free law a campaign was designed to increase understanding of the harms of SHS exposure, particularly to children, and to support enforcement of the law. The campaign featured a new television ad, Smoke-free Restaurant, highlighting specific dangers of SHS exposure for children, and emphasizing the benefits of the SF law in providing protection from these harms.

Results and lessons learnt:
A population door-to-door evaluation survey was conducted in urban and peri-urban areas of Beijing from July 1^st to August 12^th 2015 in a total of 900 households. The survey found the majority of smokers who saw the ad said it made them concerned about the effects of their smoking on their family's health (89%) and more likely to avoid exposing others to their cigarette smoke (94%). Almost all respondents said seeing the ad made them more likely to reduce their children's exposure to SHS (smokers and non-smokers both 97%). Similarly, 87% of non‐smokers said the ad made them more likely to protect themselves from SHS exposure.

Conclusions and key recommendations:
The results reflect the important role that mass media campaigns can play in supporting implementation of tobacco control policies.