Objective To learn the levels of prevalence of disease kinds the main birth defects in Sichuan province. Method According to national birth defect monitoring program,the data were collected from the hospitals monitoring the birth defects,in order to provide the basis for making more effective intervention measures. Results The first five main birth defects were external ear and other malformations(22.41/10⁴),polydactyly (14.11/10⁴),congenital heart diseases(8.81/10⁴),cleft lip with cleft palate(7.86/10⁴),cleft lip(5.12/10⁴).The diagnosis of external ear and other malformations and polydactyly was 95% after delivery,and with live birth as major outcome;The proportion of the diagnosis after delivery of the other three defects was about 60%,these defects usually were with live birth as outcome too,but the proportion of dead fetus was more than 30%. Conclusions The prevalence of the above five main birth defects is at relatively high level,so etiology or family etc research is suggested to carry out,based on the monitoring data.The ability of hospital to screen and diagnose congenital heart diseases should be improved.