Objective To explore the evolution and treatment of traumatic subdural effusion(TSE).Methods The clinicsl materials of 66 patients with TSE were analyzed retrospectively.Results 53 patients were cured with comervative therapy,and other patients were evolved into chronic subdural hematoma(CSDH).8 patients with CSDH were cured with surgery and others with conservative therapy.Conclusion Patients with TSE don't need surgery,and then patients with clinical characteristics will be operated when TSE evolves into CSDH.