Abstract: Objective: To reduce the incidence of lung infection after general anesthesia through disinfecting the anesthesic machine of internal loop.Methods: Anesthesic machines were used in four hundred cases who had no pre-operative infections and these cases were randomly divided into observation group and control group,200 cases each group;the disinfected internal loop anesthesic machines were used in these patients of observation group and,non disinfected internal loop anesthesic machines were used in those belonged to control group.Fever,productive cough,pulmonary rale,white blood cell count,chest X-ray and other indexes were monitored in two groups.Results: In observation group,pulmonary infection rate was 4.5%,while in control group,pulmonary infection rate was 16.5%,difference between the two groups had statistical significance(P<0.01).Conclusions: The use of ZJ-XD-I multi-purpose medical instrument disinfection machine to disinfect the internal loop of the anesthesic machine can effectively reduce the incidence of lung infection in the general anesthesia patients.