Abstract: Objective To analyse distributing character istic of body mass index(BMI)and its relationship with diseases of Zhejiang adults.Methods Stratified multi-stage cluster randomization was used to identify 30 counties(cities),150 to wnships(urban districts)and 9000 households.All family adults were surveyed by using self-regulating questionnaire and measured at their home.Results 23 128 respondents were valid.The average value of BMI was(23.11±2.71)among the respondents,the ratio of overweight and obesity were 28.7% and 4.8%,respectively.The ratio of overweight and obesity of urban adults were higher than that of rural ones.The ratio of overweight of male was significantly higher than that of female,while the ratio of obesity of male was lower than that of female.The ratio of over weight and obesity of the group 15~year old was the lowest and incr easing with the growing of age.The ratio of overweight of the group 45~year old was the highest (38.7%),while the ratio of obesity of the group 55~year old was the highest(8.1%).The ratio of over weight and obesity of the group of the married were higher than that of the group of unmarried and was no significant difference with the group of the divorced.The ratio of over weight of male was raising along with the growing of education level,while the ratio of obesity was no significant difference.The ratio of overweight and obesity of female were declining along with the growing of education level.The prevalence of hypertension,diabetes and cholecystit is in the group of overweight and obesity were significant higher than that of the group of normal,while the prevalence of coronary heart disease in the group of obesity was significantly higher than that of the group of normal.Conclusion The ratio of overweight of Zhejiang adults was growing in these years.The prevalence of chronic diseases such as hyper tension was increasing with BMI.