Abstract: 1°×1° NCEP reanalyze data and FY-2C satellite image TBB data are used to analyze a rainstorm process which took place in east Hubei on 12 July to 13 July 2012, The result shows that: (1) The cold art downed south while horizontal trough turned into vertical trough, the heavy rain is influenced by the mesoscale vortex development in lower layers, the stability of the mesoscale vortex and warm wet flow coming from southwest which is outside of Subtropical Anticyclone. (2) The heavy rain of east Hubei province mainly composed of two mesoscale heavy rain cloud clusters, the first rain cloud moving east because of southwest airflow outside the subtropical high peripheral was MCC, the second one moving southeast because of the cold air. (3) there was a good corresponding relation between the Lower dew-point front and the development of the heavy rain, The northern airflow through the front dew point, making low-level positive vorticity increase and development of small and medium scale vortex. (4) The interaction of dry and wet air which formed energy frontal zone, the strengthen and maintain of the energy front lead to the occurrence of the heavy rain.