Flood and waterlogging are main calamities during flood season in Lixiahe area of Jiangsu province.The calamity occurrence is closely related to the water level before precipitation.The relationship between rainfall amount and water level was determined on the basis of the special river system and topography in Lixiahe area.The forecast value of the highest water level was given according to the rainfall forecast.The essential measures can be taken in advance in term of the forecast result and therefor the flood and waterlogging damage could be reduced.