Patients underwent impacted mandibular wisdom tooth removal were randomly divided into 3 groups before operation.Patients in group A (n =41) were given pericoronal rinsing with 3 ％ H2O2 and saline before operation and irrigation once with povidone-iodine after tooth removal.Those in group B (n =43) were given irrigation with saline before and after tooth removal.47 patients in group C were given no irrigation as the controls.There was no significant difference in postoperative pain 3 days after operation among the 3 groups.Significant difference was found in postoperative pain 7 days after operation and mouth-opening 3 and 7 days after operation.There was significant difference in PoSSe scores among 3 groups but no difference between group A and B.It could be concluded that irrigation in pre-and post-operation can reduce the influence of teeth removal on life quality of the patients.