Abstract: Due to global climate changes and frequent extreme rainfalls, it is necessary to assess drainage and flood prevention system in combination with urban physical examination． Here multi-source data of land and space, such as the geographical national conditions survey, are used to establish a method to assess the following: waterlogging risk level, impact of water accumulation and waterlogging economic loss in the drainage and flood prevention system． These methods and models are applied to a District designated S in Beijing, to prove the accuracy and reliability of the method． These methods can be used in urban physical examination, and be fed back to land spatial planning and urban construction．