To probe into the significance of treating lesions in insula trans-sylvian approach in reducing cerebral injury in peri-tumor regions and post-operative complications. All patients were operated on through fronto-temporal approach. The key procedure was that arachnoid membrane in the sylvian should not only be splited sharply under microscope but also be splited from the superface till to tumors in the insula. Post-operative CT showed no signs of cerebral injury. None of all the 15 patients suffered aphasia or memory change. Trans-sylvian approach is an effective operative way in treating lesions in insula.