Abstract: The aim of this study was to analyze the statistical and structure evolutive characteristics of heavy rainfall vortexes during the flood season in Jiang-Huai valley, China, against the background of climate change, and to provide projections under two emission scenarios for the period 2020-2030, by using the regional climate model RegCM4(Regional Climate Model, version 4.0) with a horizontal resolution of 50 km.The results showed that RegCM4 can capture the environmental aspects and characteristics of this vortex type reasonably well.The simulated outputs were similar to reality in several ways, including vertical development height, lifetime, and the relative rainstorm position of the vortex.However, the simulated results were lower with respects to the number and the warmest section height of the vortex, and the background temperature and humidity, while the intensity of the vortex and velocity were higher.In terms of projection for the period 2020-2030, under the RCP4.5(Representative Concentration Pathways) scenario, the proportion of vortexes with rainstorms was shown to decrease;the vertical development height of the vortex was mainly at 850 hPa;and the life span was mostly within 2 days.The distribution of heavy rainfall and the warmest zone height were close to those in the historical period, but the intensity was weaker.Meanwhile, under the RCP8.5 scenario, the percentage of vortexes with rainstorms was projected to be greater than that under the RCP4.5 scenario;the vertical development height of the vortex was mainly at 700 hPa;the vortexes with the life span of 3 days increased;the vortex intensity enhanced;and the thickness of the warmest zone extended significantly.The moisture fronts in the vortex strengthened, but temperature fronts weakened.The study reveals that more severe vortex precipitation may occur in the future under higher greenhouse gas emissions.Further research is therefore needed on the development trends of low vortexes with severe rainfall.