Objective To explore the influencing factors and prognosis of epilepsy after operation for insular low-grade gliomas.Methods The clinical data of 120 patients with insular low-grade gliomas with pre-operative seizure symptoms in the Chinese glioma Genome Atlas Project(CGGA)database from July 2008 to June 2014 were retrospectively analyzed.The seizure control and survival prediction information of the patients were followed up one year after operation.The risk factors affecting post-operative seizures were analyzed by Logistic multiple factor regression analysis,Kapla-Meier curve was used to analyze the effect of postoperative epilepsy control factors on progression free survival(PFS)and overall survival(OS).Results Before operation,36 cases(30.0％)had simple focal seizures,53 cases(44.2％)had focal seizures with different degrees of cognitive impairment,and 31 cases(25.8％)had generalized seizures.During the follow-up after one year of surgical treatment,72 patients(60％)had a complete improvement in epilepsy symptoms(Engel grade Ⅰ),33 patients(27.5％)had a significant improvement(Engel grade Ⅱ),11 patients(9.2％)had a significant improvement(Engel grade Ⅲ),and 4 patients(3.3％)had no improvement or deterioration(Engel grade Ⅳ).Larger tumor resection degree,no putamen involved,IDH1 mutation are favorable factors for postoperative control of epilepsy.Improvement of seizures was a favorable prognostic factor for PFS and OS.Conclusion Epilepsy is the most common symptom of insular gliomas.The improvement of postoperative epilepsy symptoms is related to the degree of tumor resection,involvement of putamen and IDH1 mutation status.Complete improvement of epilepsy symptoms can prolong the progression free survival time and overall survival time of patients.