The China smog is a severe air pollution issue that has damaging effects on the health of millions of Chinese nationals and contributes to global warming. In the context of the China smog, this study examined civic engagement on social network sites (SNS) and in real life among Chinese nationals utilizing theories of uses and gratification, the effects of Internet use, media exposure, Internet censorship, political efficacy, trust and social capital. Six hundred and eighty eight Chinese nationals who are currently studying, working or residing in China completed online questionnaires. In general, the results of this study showed that a combination of high needs for recognition of SNS use and low needs for entertainment of SNS use is related with increased civic engagement. The results of this study also revealed that civic engagement is positively related with attention to content about the China smog on mobile Internet, external political efficacy and social capital.