Participants in the intervention group will receive the 'WeChat WeQuit' program from the WeChat subscription account. The period for intervention was 14 weeks, including 2-week quiting preparation intervention and 12-week postquit intervention. The number of messages/pictures/audios received by participants will gradually decrease (will be intensively sent to them during 2-week prequit and 4-week postquit, and less intensively during 5-week to 12-week postquit), and follow-up questionnaires were sent only once a month in 14-28 weeks (week 16, 20, and 26 after the quit date). A WeChat group was created for answering questions from participants, and sharing the latest resources related to quitting smoking, and promoting communication between participants.

Control group participants will not receive any smoking cessation messages by professional team. They will receive messages of thanking them for being in the study and reminding them of the time until their free month at the end of follow up. In order to measure the main two outcomes (self-reported continuous smoking abstinence and point prevalence of abstinence), continuous smoking abstinence, point prevalence of abstinence, how many cigarettes per day during the last week if they are still smoking will be checked at week 1, 4, 8, 12, 16, 20 and 26 points.

Participants who allocate to the intervention group will receive regular smoking cessation related information by professional team.

The primary outcome will be biochemical validation of self-reported 26-week continuous smoking abstinence

Self-reported 7-day point-prevalence abstinence at week 1, 4, 8, 12, 16, 20 and 26 after quit date.

Self-reported continuous smoking abstinence rate at weeks 4, 8, 12, 16, 20, and 26 after the quit date.

Reductions in number of cigarettes smoked per day and rates of participation in and completion of smoking-cessation programs.