Abstract: OBJECTIVE To investigate the differences of clinical effects of using antibiotics at different time on perioperative infection prevention of cesarean women, so as to provide references for relevant clinical infection prevention. METHODS A total of 88 cases of cesarean section women in the hospital from Dec. 2012 to Dec.r 2013 were chosen as research objects. According to the time of using antibiotics, they were divided into study group and control group, with 44 cases in each group. The study group was taken intravenous antibiotics drip 30min before surgery, and the control group was taken antibiotics intravenously after surgery. The operative time, blood loss, hospital stay, incision healing grade, puerperal infection, white blood cell count (WBC) abnormal rate, urinary system of infection, C- reactive protein (CRP) and procalcitonin (PCT) of the two groups were observed and compared. RESULTS The hospital stay of study group was (7.43±1.36) d, which was significantly lower than that of control group of (10.45±2.07) d (P＜0.05). The overall infection rate of study group was 4.55%, which was significantly lower than that of control group of 34.09%(P＜0.05). The CRP and PCT indexes in study group 1 day after surgery were (2.75±0.61) mg/L and (2.75±0.97) ng/ml, which were lower than those in control group of (4.73±0.93) mg/L and (6.78±1.94) ng/ml(P＜0.05). CONCLUSION The application of prophylactic antibiotic 30 minutes before cesarean section can effectively reduce the probability of maternal postoperative infections, and it is an effective way to prevent maternal clinical infections.