Abstract: Low Impact Development (LID) measure is a type of sustainable engineering measure to solve the urban water problems. The runoff-control rate is considerably affected by the initial hydrological conditions. Through using Storm Water Management Model (SWMM) for Tianfuheyuan Residential Community in Xixian New Area,this work simulates the runoff control and flood peak reduction under different initial conditions for LID and traditional-development measures,respectively for a set of storms with different return periods. The results indicate that:① The runoff-control rates of natural,semi-saturated and saturated LID measures are 64.3%—83.2%,56.3%—76.5% and 48.7%—68.1%,respectively. Compared to the natural condition,the runoff-control rates in the semi-saturated and saturated conditions are reduced by 6.7%—9.1% and 15.1%—15.8%,respectively. As the rainfall return period increases,the reduction value of runoff-control rate increases at the beginning but then decreases. ② The runoff peaks are 23.3—189.4 L/s,25.9—198.4 L/s and 28.8—290.7 L/s,respectively for natural,semi-saturated and saturated LID measures. In contrast with natural condition,the runoff peaks of semi-saturated and saturated conditions increase by 4.5%—20.9% and 22.9%—53.4%,respectively,indicating that the runoff-control effect of LID measures in saturated condition is far lower than that of nature condition. ③ Compared to the traditional development,LID has significant improvement for runoff control rate. The natural and semi-saturated LID measures could significantly reduce the peak runoff,but it increases under the saturated condition with the rainfall return period of 20 years,showing that the saturated LID measures may lead to higher discharge in the sewer networks downstream for heavy storms. ④ Under the same initial conditions,LID measures are able to effectively improve runoff-control rate. The research can help investigate the practical effects of LID measures.