Abstract: Objective To analyze age distribution of measles cases from 2005 through 2011 in Gansu province and to provide evidences for making policy in eradication of measles.Methods Descriptive epidemiological analysis was used to analyze age ratio of measles cases and age-specific measles incidence based on surveillance data in the province.Results During the period,the measles cases were mainly children under the age 15 years,accounting for 70.55%of all cases.There were regional differences in age distribution of the cases,with the higher proportions(>80%averagely)of cases less than 15 years old in three prefectures.In the general population,the measles incidence was inversely related to the age of the people,with the highest incidence among small children less than one year old.Conclusion The age distribution of measles cases changed greatly in Gansu province from 2005 through 2011 and the proportion of cases less than one year old increased significantly and that of cases aged 15 years or older increased slightly.