ObjectiveTo investigate the status and risk factors of surgical site infection (SSI) in  hospitals in China, so as to provide theoretical basis for the prevention and treatment of SSI. MethodsFour types of surgeries (colorectal surgery, abdominal hysterectomy, femoral neck repair surgery, and vascular surgery) in 29 hospitals were monitored prospectively, risk factors for SSI were analyzed.ResultsA total of 6 309 surgical procedures were investigated, incidence of SSI was 1.60%. Incidences of SSI in patients receiving colorectal surgery, abdominal hysterectomy, femoral neck repair surgery, and vascular surgery were 4.47%（74/1 655）,1.03%（22/2 139）,0.21%（5/2 372）,and  0.00%（0/143） respectively. The incidences of SSI were different among different regions(χ2= 114.213,P<0.05). The most common SSI was superficial incisional infection, the next was deep incisional infection. The major pathogens causing SSI were Escherichia coli, Enterococcus spp., coagulase negative staphylococcus, Staphylococcus aureus,and Klebsiella pneumoniae.The independent risk factors for SSI were male patients, long duration of surgery, and high NNIS score.ConclusionThe risk of SSI is varied with different types of surgeries. Male, long duration of surgery, and high NNIS score can increase the risk of postoperative SSI.