The outcome of acute subdural hematoma(SDH) had been generally unsatisfactory. The authors have analyzed the factors influencing the outcome of 70 patients who underwent acute SDH evacuation. Thirty five patients(50%) died and twenty two(31.4%) had a favorable outcome. A significant correlation was found between the outcome and the motor score at operation, the time interval to operation papillary response, type of operation and the Glasgow Coma Scale(GCS) at operation. But the patient's age, the mode of injury, the skull fracture, the degree of midline shift, the hematoma location, the type of brain swelling, the hematoma thickness, and the systolic blood pressure did not correlate with the outcome scale.