Abstract: The concept of volumetric precipitation (V) and its calculation methods are studied in this paper based on the Huaihe River Basin Floods in 2003.V is defined as to tal precipitation amount fromsky at a volumetric amount over an area A:V=∫AP(x,y)dA =∫∫P(x,y)dx dyThe unit of V is m3.V is important information not only to hydrology,flood control and water resource management,but also to verification of precipitation forecasts of numerical weather prediction models and to climate research.