China has experienced an epidemiological transition shifting from the infectious to the chronic diseases in much shorter time than many other countries. The pace and spread of behavioural changes, including changing diets, decreased physical activity, high rates of male smoking, and other high risk behaviours, has accelerated to an unprecedented degree. As a result, the burden of chronic diseases, preventable morbidity and mortality, and associated health-care costs could now increase substantially. China already has 177 million adults with hypertension; furthermore, 303 million adults smoke, which is a third of the world's total number of smokers, and 530 million people in China are passively exposed to second-hand smoke. The prevalence of overweight people and obesity is increasing in Chinese adults and children, because of dietary changes and reduced physical activity. Emergence of chronic diseases presents special challenges for China's ongoing reform of health care, given the large numbers who require curative treatment and the narrow window of opportunity for timely prevention of disease.