Abstract: Objective To investigate influential factors of smoking behavior among urban residents in Lanzhou city and to provide reference for preventing urban residents from smoking.Methods With cluster sampling method,1 072 urban residents aged 15 years and over were selected from two communities of Lanzhou and investigated with a questionnaire.Logistic regression was used to analysze influential factors of smoking.Results The smoking rate among the residents was 34.14%(55.07% for male and 3.02% for female) and 24.72% of the residents smoked every day.The influencing factors of smoking in the residents were gender,whether paying attention to people smoking around,familial income of last year,and the awareness of tobacco advertisements in previous 6 months.Conclusion Male population is still the key group for tobacco control in Lanzhou city.We should strengthen the laws against smoking ads to carry out tobacco control intervention.