为了在缺少实时台站数据的情况下，研究震后地表地震动分布，本文尝试通过对震源做出某些约束，以提高震动图的精度。由于青海玉树地震的发震断层近似直立( 倾向83°) ，震源破裂过程在时间和空间上呈明显的分区特征，分别考虑了地表破裂的线源发生模型和主震震级分解方法，用考虑了场地效应的震动图快速生成方法生成震动图。将两种方法生成的震动图与调查烈度比较。结果表明，基于震源破裂过程对主震震级进行分解，综合考虑各子事件生成震动图的方法，对震后的应急决策和灾情的快速评估是可行的。

In the absence of real-time data of the stations after the earthquake，this paper attempts to make some constraints from the source in order to improve the accuracy of ShakeMap． The causative fault of the Yushu earthquake is approximately vertical ( dip 83°) ，and the source process in time and space was distinctly dispersive． On the basis of the line source model of surface rupture and the magnitude decomposition method of main shock， we gnerate the ShakeMaps which takes the site effect into consideration． We compare the ShakeMaps of the above methods with intensity of investigation． The result shows that magnitude decomposition method of main shock based on source process，considering Shakemap of each sub － event，is feasible for disaster emergency response，decision-making and rapid disaster assessment after the earthquake．

地震行业科研专项201108002、201108014; 中国地震局地球物理研究所基本科研业务专项联合资助