The Southwest Vortex is one of the most powerful rainstorm systems in China,and requires greater attention from scholars,due to the fact that the previous investigations on the Southwest Vortex have not formulated its occurrence and development from different origins.In this study,the ERA-INTERIM reanalysis data with 2.5°×2.5° resolution of the geopotential height and wind with 6-hour resolution from June to August during the period of 1979-2016 were presented.According to the different origins,the southwest vortexes(SWVs) present were subdivided into Jiulong area vortexes,Sichuan Basin vortexes and Xiaojin area vortexes.The characteristics of the SWVs were statistically analyzed after defining the closed cyclone circulation and setting up the statistic method of the vortex movement routine according to wind field.Next,the climate characteristics in the SWVs anomaly years,along with the characteristics of precipitation contributed by the SWVs from 1979-2016 in summer(June to August),were quantified and analyzed emphatically.The results suggest that the annual frequency of occurrence of SWVs was 11.6 a^-1,and the maximum number of vortexes generated in the Sichuan Basin(9.3 a^-1),followed by the Jiulong area(1.9 a^-1),at least in the Xiaojin area(0.4 a^-1).As for moving rate,the Sichuan Basin vortexes reached 44.2%(the maximum),followed by 30.8% for the Xiaojin vortexes,with the Jiulong vortexes being the slowest at 29.73%.There were a total of 140 high-impact SWVs generating during the summers of the 38 years,while only 105 cases moved out of the places of origin(among them 84 Sichuan Basin,17 Jiulong and 4 Xiaojin area vortexes).The migratory paths of the high-impact Sichuan Basin and Jiulong vortexes were respectively based on eastward and northeastward-migrating paths.In order to research the relationship between migratory SWVs and precipitation,we drew a distribution map of the rain belt and strong precipitation center,and concluded that the high-impact SWVs persisting for more than 36 hours would lead to precipitation,while probability of over 88% would lead to heavy rainfall and the above precipitation.The longer the lifespan of the SWVs was,the more likely it was that the rainstorm process would be brought to the downstream area.The respective probabilities of causing heavy rainfall and the above precipitation for the high-impact Jiulong and Sichuan Basin vortexes were 83% and 91%,which had significantly higher ratios than the Xiaojin area vortexes.At the same time,the rain belt caused by the SWVs was consistent with their migratory path.The results of this study also show that,when the high-impact Sichuan Basin vortexes moved northeastward,the rain belt appeared in the areas of Hubei,Anhui and Shandong,while some also appeared in the northeast area.The heavy rainfall centers were mainly distributed at the junction of Hubei and Anhui.When the high-impact Sichuan Basin vortexes moved out along the eastward path,the heavy rainfall center was concentrated in the middle and lower reaches of the Yangtze River,where the highest occurrence frequency was found.When the high-impact Sichuan Basin vortexes moved out along the southeast path,there were two main rain belts corresponding to it,one in the Hunan,Jiangxi and Fujian area,and the other in Guizhou and Guangxi,with the latter belt appearing more frequently.The heavy rainfall center mainly occurred at the junction of Guizhou and Guangxi.