Taking a district in Nanjing as study area, using the management model of storm and flood, the paper studied the effect reconstruction of sunken lawn and porous pavement on surface runoff in study region. The simulation results showed that both concave down greenbelt and permeable pavement can effectively reduce the total surface runoff, peak flow and runoff coefficient, meanwhile it can improve the environment of groundwater in study regional. Through changing the scale of sunken lawn and porous pavement in the model, the conclusion was gotten that the ratio of the sunken lawn area to total area shall not be less than 30%; the ratio of the porous pavement area to total area shall not be less than 20%.