Objective To evaluate the efficacy and safety of radiofrequency coagulation in bilateral amygdale and anterior limb of internal capsule as a treatment for mental retardation accompanying with aggressive and impulsion behaviors. Methods 33 patients, all met diagnostic criteria of ICD- 10 and DSM-Ⅳ,were treated with bilateral anygdaloid body and anterior limb of internal capsule radiofrequency coagulation. All patients referred to surgery were previously failed to response to multiple non--surgical methods. All targets were viewable and located directly by CT. After surgery, the symptomatic improvements were evaluated by Clinical global impression （CGI） and Children aggressive scale--parent （CAS--P）, and intelligence quotient （IQ） was assessed with Wechsler intelligence scale （WIS）. Results The total efficiency was 91.5% at 24 month follow--up （excellent for 5 cases,significant improved for 16 cases, improved for 9 cases and no change 3 for cases）with CGI evaluation. Postoperative scores of CAS--P were significant decreased from 67 to 15.2 at 6 month follow--up,and 16 at 24 month follow--up. The IQ average score was improved slightly from 35.88 to 36.24. One patient had a small intracerebral hematoma,and complete rehabilitated two weeks later. One patient experienced a hemiplegia and improved two weeks later. Transient complications include hyperpyrexia （3 cases）,hypersexuality （2 cases） and hyperorexia（2 cases） ,and recovered within two weeks. Conclusions Bilateral amygdaloid body and anterior limb of internal capsule stereotactic radiofrequency coagulation is proven a safe and effective for MR accompanying with aggressive and impulsion behavior,it provide a significant short and long term effect, without severe or permanent complications.