ObjectiveTo evaluate the status and influencing factors of surgical site infection(SSI) in colorectal cancer patients.MethodsA retrospective investigation was conducted to analyze the medical records of 420 colorectal cancer patients who were hospitalized between January 2007 and December 2011.ResultsSSI rate in 420 patients was 20.24 % (85/420); 75.29%(64/85) were superficial incisional infections, 22.35%(19/85) were deep incisional infections, 2.35%(2/85) were organ space infections. A total of 98 pathogenic strains were isolated, 56.13% (55 isolates) were Escherichia coli. The incidence of SSI increased significantly in patients with overweight or obesity (BMI≥23), diabetes mellitus, operative duration more than 3.5 h and high Dukes stage (all P<0.05).ConclusionSSI rate in colorectal cancer patients is high. Overweight or obesity, diabetes mellitus, long operative duration and the high Dukes stage are important factors for SSI in colorectal cancer patients．