Abstract: A heavy rainfall process occurred in Dali prefecture on July 14,2011.The routine observed data and the wind-profiling radar data are used to analyze the impact system,the characteristics of physical quantities and so on before and during the rainfall process.The results show that:the mainly impact system of the regional heavy rainfall process was the monsoon trough in 500hPa and the shear line in 700hPa;The formation of deep high-humidity layer provided plentiful vapor for the heavy rainfall process.Other characteristics of physical quantity field including lower-level convergence,upper-level divergence,lower level positive velocity and upper-level minus velocity were obvious before the heavy rain.Meanwile,Dali district was located in the area with instability and high energy tongue at the middle low lever.The E index which characterizes dynamical and thermal diagnosis has certain indication to the area of heavy precipitation.The negative vertical velocity of wind profiler radar data showed foretelling effects on the occurrence of the heavy rainfall and its intensity.There was a very close relationship between signal-to-noise and the intensity of heavy rainfall.And the horizontal winds showed obvious discontinuous feature with height changing during the rainfall process.