First stage, the study will investigate and register the basic information of emergency treatment management for the acute aSAH in 20 different grade centers located in different economic levels districts including Northeast part, Northern, Eastern, South-central, Northwest, Southwest and Qinghai-Tibet of China. Comparing the the outcome of acute aSAH to find the critical factors to affect it by statistical analysis. Then,the investigators will offer some suggestions to adjust the measures to improve the efficacy of emergency medical service for acute SAH.