Objective To realize the incidence of surgical site infection (SSI) monitored with different methods, so as to provide reference for reducing infection rate and making infection control measures. Methods SSI  occurred in patients with gastrointestinal tract operation in a hospital between July, 2007 （before performing targeted monitor, control group） and June, 2008 （after performing targeted monitor, monitored group）was compared. Results SSI in control and monitored group was 12.30% and 7.00% respectively, there was significant difference between two groups( χ2=3.98, P<0.05). Conclusion Targeted monitor can effectively reduce nosocomial infection rate.