Abstract: Objective To evaluate the effect of mother-to-child transmission of syphilis program and explore the influencing factors of the program.Methods The data of pregnant women infected by syphilis during 2015-2018 were collected. The situation of maternal syphilis infection,the situation and effect of maternal and infant blocking service for pregnant women with syphilis infection were analyzed.Results From 2015 to 2018,the detection rate of syphilis,the detection rate of pregnancy and the proportion of diagnosis during pregnancy in Jilin Province increased year by year,the treatment rate of pregnant women with syphilis infection and the preventive treatment rate of children born by syphilis-infected mothers increased year by year,and the reported incidence of congenital syphilis decreased year by year. The difference was statistically significant (P<0.05).Conclusion The risk of congenital syphilis decreased through the implementation of prevention of mother-to-child transmission of syphilis. It should be reinforced for the treatment of pregnant women infected by syphilis and the children born by syphilis-infected mothers.