Objective: To analyze under 5 years old mortality rate during 2016-2021 in Xicheng District, Beijing, and to provide scientific basis for further reducing infant mortality rate and under 5 years old mortality rate. Methods: A descriptive statistical analysis was conducted on the mortality surveillance data of children under 5 years old reported by Preventive Health Department of Xicheng District Community Health Service Center during 2016-2021. Results: During 2016-2021, under 5 mortality, infants and newborn mortality in Xicheng District decreased from 2.31‰, 1.85‰ and 1.12‰ to 1.55‰, 1.07‰ and 0.48‰ respectively. There was no significant difference in mortality rate between 2016 and 2021( P >0.05). The leading cause of death among children under 5 years of age included other congenital abnormalities(except congenital heart disease and down s syndrome)(18.79%), preterm birth/low birth weight (16.36%) and birth asphyxia(7.88%). Infant deaths accounted for 69.23%- 80.00 % of deaths of children under 5 years of age, and neonatal mortality accounted for 44.44%-71.43% of infant mortality. Conclusion It is necessary to carry out relevant preventive intervention and quality management based on the main causes of death, and to further improve the management of critically ill neonates and reduce neonatal mortality.