Abstract: OBJECTIVE To investigate the group B Streptococcus infection in perinatal women,so as to provides a theoretical basis for the clinical studies of pregnancy outcomes.METHODS A total of 725 cases of perinatal women from Jan.2013 to Jan.2015 in our hospital were selected as the objects of study.Bacterial cultures and real-time quantitative polymerase chain reaction（RT-PCR）were used for positive test of group B Streptococcusin perinatal women,and the impact of group B Streptococcus to pregnancy outcome in perinatal women was analyzed.RESULTS There were 36 cases of positive group B Streptococcus bacterial were cultured,and the positive rate was4.97%.RT-PCR detected out 80 cases positive,and the positive rate was 11.03%,and the difference was significant in these two ways（P＜0.05）.The comparison of specificity,sensitivity and degree of accuracy between bacterial cultures and RT-PCR to check the group B Streptococcus had significant difference（P＜0.05）.The incidence rates of intrauterine infection,postpartum hemorrhage,fetal distress and neonatal infection in GBS positive perinatal women by RT-PCR were16.25%,17.5%,2.5%,36.25%and 13.75%.CONCLUSION RT-PCR method is better for perinatal women to have detection results of group B Streptococcus with high accuracy,excellent specificity.The group B Streptococcus infection in perinatal women will have higher postpartum hemorrhage rate,increasing the probability of infection of the uterus,as well as higher malformation rate of neonatal.The group B Streptococcus in perinatal women has important implications on pregnancy outcome,which is worth to concern in the clinical application.