Abstract: Objective　The study was conducted to investigate the birth defect of newborn infants in Wenzhou city. Methods　Report cards for newborn infants with birth defects were filled by doctors and the data were collected every three months to conducted statistical analysis according to the requirement of National Birth Defects Surveillance Network. Results　From 2005 to 2007, 307, 431, and 567 birth defect cases occurred respectively with the incidence rate of 0.76%, 0.95% and 1.09 %. The deaths caused by birth defect accounted for 32.20%, 39.67% and 42.42% of newborn infant death respectively. In these 3-year, there were 372 cases of congenital heart disease, which had ranked at the top place of birth defect in Wenzhou. 20 to 30-year-old women accounted for the lowest proportion among the women who delivered infants with birth defect (0.84%). Environmental factors may be highly risk for inducing birth defects. Conclusion　The incidence rate of birth defect increased progressively in the past three years, and the deaths caused by birth defect accounted for a significant higher proportion among newborn infant deaths. Therefore, it is vital to promote pre-marital medical examination and prenatal screening, improve the prenatal diagnosis and conduct neonatal diseases screening in order to improve the population quality.