ObjectiveTo understand the occurrence of surgical site infection (SSI) following class I incision operation in a tumor hospital, explore the continuous surveillance and improve effectiveness, so as to provide reference for further intervention.MethodsTargeted surveillance on thyroid surgery patients undergoing class Ⅰ incision operations in a hospital in JanuaryJune 2013 were performed by medical record review, bedside observation,  dressing change observation  and patient followup, the surveillance result was compared with that of the same period of 2010. ResultsThere was one case of SSI in JanuaryJune 2013 and  JanuaryJune 2010 respectively, SSI rate was 0.20% and 0.18% respectively，there was no significant difference（P=1.000）. In JanuaryJune 2013, prophylactic perioperative antimicrobial usage rate was 0.20%，which was lower than 27.21% of 2010; the coincident rate of indication for antimicrobial use was 100%, which was higher than 6.67% of 2010, the difference was statistically different(all P＜0.001）. ConclusionTargeted surveillance on SSI is helpful for the rational perioperative use of antimicrobial agents, the reducing of antimicrobial prophylactic use doesn’t lead to the increase of class Ⅰ incision SSI.