Objective：To investigate the status of Group B Streptococcus（GBS） colonization in pregnant women in Chongqing and analyze the impact on pregnancy outcomes. Methods：A total of 454 pregnant women were selected as the research objects. The vaginal swabs and anal swabs were taken for examination，and GBS test and drug sensitivity test were performed. The impact of GBS col－onization on pregnant women and newborn outcomes was statistically analyzed. Results：①Among 454 pregnant women，33 were posi－tive anal swab，28 were positive vaginal swab and 25 were positive for both. Either swab is positive was regarded as pregnant women complicated with GBS positive rates and the GBS positive rate in the whole group of pregnant women was 7.9%（36/454）. ②A total of 46 strains of GBS were isolated. The susceptibility test showed that the sensitivity of cefixime and vancomycin were 97.83% and 100%，respectively. The sensitivity of roxithromycin，clindamycin and levofloxacin was only 21.74%. 23.91% and 19.57%. ③Com－pared with the GBS-negative group，the incidence of premature rupture of membranes，chorioamnionitis，and postpartum hemorrhage in the GBS-positive group were significantly higher（P<0.05）. ④GBS colonization had adverse influences on newborns. Compared with the GBS-negative group，the incidence of adverse outcomes such as neonatal pneumonia，neonatal sepsis，hyaline membrane disease，neonatal asphyxia，and amniotic fluid fecal infection in the GBS-positive group was significantly higher（P<0.05）. Conclusion：GBS colonization has obvious adverse effects on pregnancy outcome and neonatal outcome. Cefixime is more sensitive to GBS and can be used as the best choice for preventing infection.