Objective To explore the etiology and epidemiological characteristics of fever and rash syndrome a mong children under the age of five years in Northwest China from 2009 to 2015.Methods Descriptive epidemiological analysis was conducted based on the monitoring data in sentinel hospitals,which was from the information management system of national infectious disease monitoring from 2009 to 2015 in Gansu,Qinghai,Inner Mongolia and Xinjiang.Results The results showed that the major pathogens of fever and rash syndrome among children under the age of five years were enterovirus,measles virus,varicella-zoster virus (VZV) and rubella virus.The major pathogens among children in the age group of 0-years and in the age group of 1-5 years were measles virus and enteroviruses,respectively.Among the positive cases of enterovirus,the positive detectable rates of human enterovirus 71 (EV71) and coxsackie A16 (CA16) were 47.18％ and 45.59％,respectively.The incidences of enterovirus and measles virus infection were mainly concentrated on May to July and March to May,respectively.Conclusions The major pathogens of fever and rash syndrome among children under the age of five years in Northwest china were enterovirus and measles virus with seasonal epidemic characteristics.Therefore,the prevention and control of measles and hand-foot-mouth disease should be strengthened.