Abstract: With increasingly frequent and severe urban flooding disasters, construction of sponge cities that is based on the low impact development (LID) technology, is becoming a new principle for urban storm water management in China. In this study, a storm water management model (SWMM) was developed to simulate the flooding in the Qinghe catchment in Beijing, and urban rainfall-runoff processes in the conditions of different scales of LID measures and different return periods of design storms were simulated and analyzed. The results showed that for shorter return-period storms, reduction in peak flow and runoff volume achieved by combining these measures was up to 66.2% and 49.4%, respectively, while for extreme floods, the reduction in runoff volume was only 11.5% and no considerable reduction in peak flow was achieved. This indicates that the adopted LID facilities are effective in changing the rainfall-runoff processes of shorter return-period storms but ineffective in reducing floods of longer return periods. This conclusion is helpful for flood control, drainage management, and construction of a sponge city in Beijing.