Based on the characteristic analysis of urban stormwater,this paper has proposed the method and steps of establishing the synthetic instantaneous unit hydrograph in urban area.

• 通过对城市化流域雨洪特点的分析，提出用综合瞬时单位线法建立城市雨洪系统综合汇流模型的方法与步骤，并根据北京市实测水文资料进行了实例研究。