Abstract: Objective To examine the mortality and the influence on life expectancy of malignant tumor in Xinyuan couty,Xinjiang Uygur Autonomous Region.Methods International Classification of Diseases-10th Revision(ICD-10),was used for death cause code.The life expectancy,mortality,the potential years of lost(PYLL),and the rate of potential years of life lost(YPLL‰) were calculated.Results The average life expectancy of the population in Xinyuan couty was 70.8 years.The life expectancy of Kazakh,Han and Uygur population was 62.1,80.3,and 69.6 years,respectively.The life expectancy excluding deaths from malignant tumors was 74.6,65.3,84.3,74.7 years for total population,Kazakh,Han,and Uygur population,respectively.The overall mortality rate of malignant tumor was 86.7 /100 000(103.5/100 000 for men and 67.6/100 000 for women,χ²=40.6,P<0.001).There were significant differences in the mortality rate among Kazakh,Han,and Urgur population(χ²=35.6,P<0.001).The PYLL of cancer was 11 922 person years(7 366.5 for men,4 555.5 for women) for total population and 7 063.5,3 154,and 1 132 person years for Kazakh,Han and Uygur population,respectively.Conclusion Malignant neoplasms is the main cause of death among the inhabitants in Xinyuan county.Comprehensive intervention measures should be implemented to decrease the prevalence of malignant neoplasms among different ethnic populations.