Objective To explore the 3+1 monitoring mode for birth defects and quality control measures based on the population,and to obtain the related information data for birth defects.Methods With the community population as the basis,adopting the unified monitoring scheme dominant by the leadership and administration of govment,with districts(counties)as the monitoring sites,the 3+1 monitoring mode for birth defects was based on a complete monitoring team with the combination of villages/residents’committees,townships(towns),counties(districts)and the municipality.Demonstration research was carried out in the pilot districts/counties in Chongqing City.Results Birth defects population monitoring system based on population and family planning management and service network was established,and during 2005 and 2006,application research was carried out for the monitoring methods among birth deflects population in the pilot districts(counties),obtaining the relevant information in regional birth defects,with a monitoring coverage of over 99%.Conclusion Fully utilizing the birth management functions of Population and Family Planning System and the advantages of service networks,long term,dynamic birth defects monitoring system based on community population was established,with the integration of birth defects monitoring and regular reproductive health services,obtaining overall birth defects occurrence information in details,providing scientific basis for the govment to formulate scientific,practical,economic and effective birth defects intervention policy,so as to improve the quality of the population.