Abstract: Objective To investigate the relationship between body mass index(BMI) and the levels of blood lipid and lipid metabolic disorder among middle-aged and elder people.Methods Stratified cluster sampling method was used and 5 175 persons aged 40-79 years in Chengdu city were selected for a questionnaire survey and measurements of height,weight,and blood lipid.Results The prevalence of obesity was 11.03% (8.66% for male and 12.6% for female) and that of overw eight was 35.07% (35.70 for male and 34.70% for female) among the people.With the increase of BMI,triglyceride(TG) levels in the older aged groups showed an increase trend and high-density lipoprotein-cholesteral(HDL-C) levels show ed an obvious decrease.With BMI increase,the middle-aged male show ed a trend of high TG hyperlipidemia.The female show ed a increase trend of high TG hyperlipidemia,high total cholesterol(TC),and low HDL-C with the increase of BMI.Conclusion BMI is closely corelated with the incidences of high TG,high TC,low HDL-C among middle-aged and elder persons.