Abstract: Objective To investigate the prevalences of overweight and obesity and their associations with chronic diseases among residents in Yuhuatai district of Nanjing city.Methods With systematically stratified sampling method,residents aged 15 years or more in Yuhuatai district were selected and surveyed.Logistic regression was applied to investigate the relationship between body mass index(BMI) and chronic diseases.Results Among all residents enrolled in the survey,a total of 12 627 subjects provided qualified questionnaires and were included in the analysis.The average BMI among the residents was23.64±2.91 kg/m²,and the proportions of overweight and obesity were 35.43% and 7.29%,respectively.The proportion of overweight in the male residents was significantly higher than that in the female residents(P<0.05),but there was no statistical significant gender difference in the proportion of obesity(P>0.05).Overweight and obesity were positively correlated with smoking and moderate- and high-salt food intake,with the odds ratios(ORs) of 1.22,1.28 and 1.47.The residents with mild physical activity,sleeping time of 6-8 hours and more than 8 hours had less risk of obesity,with the ORs of 0.79,0.91,and 0.77.The subjects with overweight or obesity had higher risks of hypertension,diabetes,coronary heart disease,stroke,chronic obstructive pulmonary disease,and hyperlipidemia with the relative risks(RRs) of 1.65,1.55,1.27,1.49,1.06,1.87 and 2.38,2.39,1.54,2.07,1.69,4.26,respectively.Conclusion The proportion of overweight and obesity in the residents of Yuhuatai district in Nanjing city was high.Systematic intervention should be conducted and may be useful for control of chronic diseases.