Abstract: Objective To understand the occurrence of birth defects in Hengyang City by analyzing the monitoring results of birth defects in Hengyang Hospital from 2016 to 2018,and to provide a basis for the formulation of comprehensive prevention and control policies for birth defects in the future.Methods According to the requirement of birth defects monitoring in the "China Maternal and Child Health Monitoring Program" formulated by the National Maternal and Child Health Monitoring Center,data from 175 monitoring hospitals in Hengyang City were collected and analyzed.Results A total of 215294 perinatal infants were monitored from 2016 to 2018,and 2793 cases were with birth defects. The total incidence of birth defects was 129.73/10000.There were 1802 cases of birth defects ≥ 28 weeks,the incidence rate was 83.7/10000.The incidence of birth defects in males(96.43/10000) was higher than that in females(67.96/10000),and the difference was statistically significant. The incidence of birth defects in the ≥ 35 years old groupwas significantly higher than that in other age groups. The top ten birth defects were congenital heart disease,cleft lip with cleft palate,polydactyly,other external ear deformities,kidney deformities,equinovarus,Down's syndrome,syndactyly,congenital hydrocephalus,limb shortening and cleft lip.Conclusion The incidence of birth defects in Hengyang City is lower than the national level,but comprehensive prevention and control of birth defects should be strengthened to reduce the incidence of birth defects and improve the quality of the birth population.