Abstract: OBJECTIVE To understand the effect of intraoperative re-dosing of antibiotics on prevention and control of surgical site infections in patients undergoing clean surgery in a three-A general hospital. METHODS By means of epidemiological experiment, a self comparison was conducted, the first stage was from Jan 1, 2012 to Dec 31, 2013, the prospective, targeted monitoring of surgical site infections was carried out for the patients who underwent the clean surgery (the type Ⅰ incision) so as to understand the incidence of the surgical site infections. The second stage was from Jan 1, 2014 to Dec 31, 2015, the intervention measures were taken and the proportion of intraoperative re-dosing of antibiotics was raised so as to reduce the incidence of surgical site infections. The effects on prevention and control of the surgical site infections were evaluated before and after the interventions were taken. RESULTS Of totally 23 622 case-times of patients who underwent the clean surgery during the observation period, 43.9% were more than 65 years old, 57.9% (14 418 case-times) were females, 88.6% were with the ASA score varying from Ⅰ to Ⅱ, and 99.2% received 23 434 selective surgeries.The proportion of the antibiotics prophylaxis for the clean surgery was 26.9%, the proportion of the drug administration at 0.5-2 hours before skin incision was 93.4%, and the proportion of drug withdrawal after the surgery for 24 hours was 65.3%; there was no significant difference in the three above indexes before and after the intervention.The incidence of SSI dropped from 0.7% before the intervention to 0.4% after the intervention, with the RR value 1.608(95%CI:1.130-2.288).The incidence of SSI in the patients with operation duration no less than 3 hours dropped from 5.9% before the intervention to 1.8% after the intervention, with the RR value 3.432(95%CI:1.764-6.675).The proportion of the intraoperative re-dosing of antibiotics ascended from 44.2% to 70.7%, and there was significant difference (χ²=89.861,P＜0.05). CONCLUSIONS The intraoperative re-dosing of antibiotics can effectively reduce the incidence of the surgical site infections in the patients undergoing the clean surgery and provide guidance for further prevention and control of the surgical site infections.