Objective To explore the association between air pollution and the pregnancy outcome in a severe air pollution city and to provide the evidence for health related policy-making.Methods The subject population included the newborns from 1997 to 2004 in Taiyuan and the data of air pollution in the same time were collected.Logistic regression was used to analyze OR in the case-control design.Results Statistically,the prevalence of premature birth,birth defects and the mortality of infants and fetuses were significantly associated with PM10 air pollution.For premature birth,odds ratios were ranged from 1.17 to 1.76,the highest OR,1.76(95%CI:1.64-1.90),was found during the first 3 months of pregnancy.For birth defects,odds ratios were from 1.37 to 1.67,the highest OR,1.67(95%CI:1.28-2.17),was found in the third month.Concerning mortality of infants and fetuses,it only showed a significant association in the third trimester and the OR was 1.66(95%CI:1.26-2.19).Regarding SO2 air pollution,it only showed the significant effect on premature birth during the first and second month,the odds ratios were 1.27(95%CI:1.21-1.34)and 1.07(95%CI:1.01-1.14)respectively.Conclusion Air pollution in the investigated city had an adverse effect on the pregnancy outcome and the stringent measures should be taken to abate the air pollution and to reduce the risk for reproductive health.