Abstract: Objective To study the prevelence and distribution of dementia among the elderly in urban communities of Guiy ang city.Methods Using multistage sampling,the data were collected to 3229 old people aged 60 years and ov eramong 26 communities of Guiyang.All participants were interviewed and screened with M ini-mental State Examination(M M SE).Dementia was diagnosed by using DSM-IV.The diag nosis of Alzheimer.s disease(AD)and vasculardementia(VD)used NI NCDS-ADR DA and N IN DS-AI REN criteria,respectively.Chi-square test and o dds ration(OR)were used to data analysis.Results Totally 64 cases of dementia were identified,41 were AD(64.06%),18 were V D(28.13%),2 were mixed dement ia(3.13%),and 3 were other kinds of dementia(4.68%).The prevalence of dementia,A D and V D among old people aged 60 and overwere 1.98%,1.27% and 0.56%,respectively.The rates of dementia,AD and V D were usually along with the increasing age.There was no statistically significance forthe prevalence between men and women.Tere was a decreasing tendency fordementia and A D with the increasing years of schooling.The manual workers had a hig herprevalence o f A D than mental workers.The widowed people had higherprev alence of dementia and AD than those of living with spouse.Conclusion The prevalence rate of AD in Guiyang was similarto urban average rate in ourcountry.A D was the main type of dementia.Aging,loweducation and widowed old people were associated with dementia.