AIM: To study the influence of high-frequency electric surgical knives on healing of abdominal incision.METHODS: Two hundred and forty white rats were divided into 100, 102, 105, and 108 groups and rat models of abdominal operation were induced by using electric surgical knives and common lancets respectively.Then they were respectively given hypodermic injections of normal saline and 0.2 mL quantitative mixture of Escherichia coli, Staphylococcus aureus and Pseudononas aeruginosa at a concentration of 102, 105 and 108. On the basis of the animal experiment, 220 patients undergoing abdominal operations (above type Ⅱ) were randomly allocated into one of following three groups: electric knife (EK, 93 cases), electro-coagulation (EC, 55 cases) and control (72 cases). High-frequency electric surgical knives were used to dissect abdominal tissues and electro-coagulation for hemostasis in EK group. Common lancets and electro-coagulation were applied in EC group. Common lancets and tieing silk suture were used in the controls.RESULTS: Tn all the groups except group 100, infection rate of incisional wounds made by electric surgical knives were remarkably higher than that with common lancets.Furthermore, there were significant differences in groups 102, 105,and 108 (P ＜ 0.05), but not in group 100 (P ＞ 0.05) between EK and EC groups. Clinical studies showed a delayed wound healing in 16 cases (17.20%) in EK, 11 cases (16.36%) in EC and 2 cases (2.86%) in the control groups. A significant difference between EK and the control groups (x2= 8.57, P ＜ 0.01), and between EC and the control groups (x2 = 5.66, P ＜ 0.05) was observed, but not between EK and EC (x2 = 0.017,P ＞ 0.05).CONCLUSION: High-frequency electric knives may remarkably.delay abdominal incision healing. Its application should be minimized so as to reduce the possibility of postoperative complications.