Abstract: Objective To examine the prevalence of knee osteoarthritis(KOA)among inhabitants of Uighur,Kazak,and Han nationality in pastoral areas of north of Xinjiang Uygur Autonomous Region(Xinjiang)and to provide evidences to local health administrative departments for making relevant health policy.Methods Cluster random sampling method was used to select 3 402 Uighur,Kazak,Han residents in Yili,Tacheng,and Aletai in pastoral areas of north Xinjiang for a questionnaire survey and examination of knee joint.Results In the participants,the prevalence of KOA was 27.0%;the prevalence of KOA in the males was 18.6% and significantly lower than that in the females(34.8%)(χ²=113.36,P<0.01);the prevalence rates of KOA were 21.5%,31.6%,and 31.7% for the residents aged 38-49,50-59,and more than 60 years,with a statistically significant difference among different age groups(χ²=46.59,P<0.01);the KOA prevalence rates were 24.2%,37.7%,and 19.3% for the residents living in Yili,Tacheng and Aletai area,with statistically significant regional difference(χ²=93.01,P<0.01);the KOA prevalence rates were 29.6%,35.1%,and 18.1% for Uygur,Kazak and Han residents,with a statistically significant difference among different ethnic groups(χ²=89.83,P<0.01).Conclusion The prevalence rate of KOA is high and there are gender,age,ethnic,and regional differences in the prevalence rate among Uygur,Kazak,and Han residents in pastoral areas of north Xinjiang.