目的　探讨择期剖宫产术中应用头孢类抗生素对生殖道菌群的影响。方法　将 45例择期剖宫产者随机分为 3组 :A组 15例 ,手术前、后均不应用任何抗生素 ;B组 15例 ,术后常规应用头孢类抗生素 3d ;C组 15例 ,术中一次性应用头孢类抗生素。每例分别在术前、术后行阴道液、宫腔液细菌培养 ,观察手术前、后生殖道菌群变化和术后感染情况。结果　患者术前生殖道细菌培养的阳性率为 35 .71% ,术后为 6 4.2 9% (P <0 .0 1)。A组手术前生殖道中的厌氧菌和需氧菌比例为 10∶3,术后二者比例为 18∶16 ,手术前、后均以厌氧菌为多 ,B、C两组术后的需氧菌株数 ( 2 7株 )多于厌氧菌 ( 2 0株 )。 3组间术后宫腔细菌培养阳性率接近 ,术后感染率均为 6 .6 7%。但C组术后阴道、宫腔的菌株数较A、B组为少。结论　剖宫产术中应用抗生素容易出现生殖道菌群失调。剖宫产术后应合理应用抗生素 ,为减少其对生殖道正常菌群的影响 ,以术中一次性使用抗生素预防感染的方法为好 Objective To investigate the effect of cephalosporin antibiotics on genital flora during elective cesarean section. Methods 45 cases of elective cesarean section were randomly divided into 3 groups: 15 cases in group A, without any antibiotics before and after operation; 15 cases in group B, 3 days after cephalosporin antibiotics, 15 cases in group C In a one-time use of cephalosporins. Each case was preoperative and postoperative vaginal fluid, uterine fluid bacterial culture, observation of preoperative and postoperative genital flora changes and postoperative infection. Results The positive rate of preoperative genital tract bacterial culture was 35.71% and 6 4.29% (P <0.01) after operation. The ratio of anaerobic and aerobic bacteria in pre-operative genital tract of group A was 10: 3, and the ratio of the two was 18:16 after surgery. There were more anaerobic bacteria before and after operation in group A Aerobic strains (27 strains) more than anaerobic bacteria (20 strains). The positive rates of intrauterine bacterial culture in 3 groups were close, the postoperative infection rate was 6.76%. However, the number of bacteria in the vagina and uterine cavity in group C was less than those in group A and B after operation. Conclusion Antibiotics in cesarean section is prone to reproductive tract dysbacteriosis. After cesarean section should be rational use of antibiotics, in order to reduce its normal genital tract flora, intraoperative use of antibiotics to prevent infection as a good method