Abstract: Objective To explore prevalence trend and associated factors of birth defect among perinatal infants in Guangdong province between 2006 and 2015,and to provide evidences for developing and evaluating birth defect intervention program.Methods Surveillance data on birth defect from 2006 through 2015 in Guangdong province were collected for retrospective description and trend analysis.Results The total incidence of birth defects among perinatal infants was 276.80/10 000 (26 040/2 024 583) during the 10-year period;the incidence was higher than that in other provinces and showed an increasing trend (Z=1.99,P=0.04).Significant difference in the incidence was observed between male and female perinatal infants (33 629 males,21 976 females,435 unknown gender,χ²=758.24;P<0.001),among the puerperas of different age (P<0.01),and between puerperas living in urban and rural regions (26 896 in cities or towns,28 981 in villages,χ²=35.30;P<0.001).The top five birth defects with high incidence in Guangdong province were congenital heart disease,glucose-6-phosphate dehydrogenase deficiency,hydrops fetalis syndrome,polydactyly,and club foot,which was replaced by syndactly in 2015.Conclusion The registered birth defect incidence was high and comprehensive prevention measures are warranted in Guangdong province.