OBJECTIVE： To provide reference for rational prophylactic use of antibacterial drugs in cesarean section. METHODS： Retrospective investigation used in analyzing the use of antibacterial drugs between 472 patients underwent cesarean section 0.5-2 h before the operation from Jan to Dec. in 2013 and 431 patients after umbilical cord clamp during cesarean section from Jan. to Dec. in 2014. RESULTS： After intervention， the reasonable rate of the opportunity to use prophylactic antibacterial drugs was 100％， the reasonable rate of selected drugs varieties increased from 64.41％ to 93.50％， and the rate of reasonable treatment course increased from 50.21％ to 92.11％， that of usage and dosage also had a noticeable improvement， with statistical significance compared to before intervention （P＜0.05）. Antibacterial cost per capita decreased from （103.25±13.62）yuan to （54.61±27.21）yuan after intervention， and hospitalization cost per capita decreased from （5 574.8±117.6）yuan to （5 427.4±106.7）yuan， with statistical significance compared to before intervention（P＜0.05）. CONCLUSIONS： Clinical pharmacists can improve the reasonable rate of antibacterial drugs for prophylactic use in cesarean section by pharmaceutical intervention， it can make the use of antibacterial drugs more standardized and reasonable.