To determine the most prominent individual and interpersonal triggers to quit smoking in China and their associations with sociodemographic characteristics. Data come from Waves 1-3 (2006-2009) of the International Tobacco Control (ITC) China Survey, analysed cross-sectionally as person-waves (N=14,358). Measures included sociodemographic and smoking characteristics. Those who quit between waves (4.3%) were asked about triggers that 'very much' led them to stop smoking, and continuing smokers about triggers that 'very much' made them think about quitting. Triggers covered individual (personal health concerns, cigarette price, smoking restrictions, advertisements, warning labels) and interpersonal factors (family/societal disapproval of smoking, setting an example to children, concerns about secondhand smoke). Over a third of respondents (34.9%) endorsed at least one trigger strongly; quitters were more likely than smokers to mention any trigger. While similar proportions of smokers endorsed individual (24.4%) and interpersonal triggers (24.0%), quitters endorsed more individual (61.1%) than interpersonal (48.3%) triggers. However, the most common triggers (personal health concerns; setting an example to children) were the same, endorsed by two-thirds of quitters and a quarter of smokers, as were the least common triggers (warning labels; cigarette price), endorsed by 1 in 10 quitters and 1 in 20 smokers. Lower dependence among smokers and greater education among all respondents were associated with endorsing any trigger. Individual rather than interpersonal triggers appear more important for quitters. Major opportunities to motivate quit attempts are missed in China, particularly with regard to taxation and risk communication. Interventions need to focus on more dependent and less-educated smokers.