By using ECWMF(European Centre for Medium-Range Weather Forecasts) analysis data, conventional observations, FY-2C satellites, radar stations and automatic weather station data, the heavy rain occurred on the night of 28 June 2009 in Fa'er Village, Shuicheng County in Guizhou Province is analyzed.The results show that the occurrence of the heavy rain on 28 June 2009 in Fa'er Village, Shuicheng County of Guizhou Province was the result of the southern branch trough, low shear and strong southwest warm air.Area of strong precipitation was in accord with middle-γ scale cloud.The movement, mergence, development, stagnation and decline of the clouds can well indicate the rainfall area and intensity.The strong convective echoes monomer resulted from the low -level convergence zone lingered around the Wumeng mountains(highest peak 2901 m) to northwest of Shuicheng County, which merged the rain clouds to the south of the county and thus caused the heavy torrential rain.The air flow field near Fa'er was changed because of its special terrain.It did not only strengthen and maintain terrain vertical velocity but also included more water vapor into the clouds and thus prolonged the duration time of the rainstorm cloud above Fa'er.The trumpet shape of the terrain also strengthened the convergence upward movement.The regional AWS data shows that the small and medium-scale weather system exerted important influence on the rain in Fa'er Village and nearby areas.It is also significant for the short-term forecast of this heavy torrential rain.