Abstract: Objective To master the situation of child deaths under 5 years in bayinnaoer city, to analyze the constitution of causes and trends of death, and to provide the evidences for the government to make effective intervention measures to reduce the mortality of children under 5 years.Methods The monitoring data of the deaths of children under 5 years from 2011 to 2016 in bayinnaoer city were analyzed.Results During the 6 years, the mortality of children under 5 years, the infant mortality and the neonatal mortality generally showed the decline trends.The neonatal death accounted for 76.40% of all deaths of children under 5 years.The sequence of the top five main causes of deaths, as the following:preterm low birth weight, other congenital anomaly, birth asphyxia, congenital heart disease, other neonatal illness.They accounted for 74.80% of all deaths of children under 5 years.The accidental injury deaths of 1-4 years old children accounted for 33.33% of all deaths of this age group children.Conclusion It is necessary to improve the management of prenatal health care, to pay attention to the screening and referral of the pregnant women with high risks, to strengthen the perinatal care, to prevent premature delivery, and to reduce the incidence of birth defects.To reduce the incidence of accidental injury of children can effectively reduce the mortality of children under 5 years and improve the quality of birth population.