Based on the satellite water vapor image combining with visible picture and radar data and conventional observation,the paper analyzed the strong convective system in Peixian of Jiangsu Province on 5 June 2009.The results show that the junctions of satellite water vapor imagery abnormal dynamic areas and convection systems as well as the two convection cloud clusters effluent boundary in the visible image produced the strong convection weather such as tornado easily.The water vapor conveyors in the water vapor imagery were consistent with convection cloud systems in the visible image.Water vapor imagery feature is connected with the large scale weather process which resulted in vertical motion and air current deformation field.The water vapor imagery stands for dynamic feature of hightroposphere.Strong convection often occurs in the low brightness temperature cloud clusters.High space-time resolution satellite and radar image can reflect the strong convective system very well and offset the insufficiency of conventional observation to provide a reference for the short-time weather forecasting.