Abstract: Based on the NCEP1°×1° reanalysis data and satellite data,the contrast analysis of two heavy rainfall cases in Kunming is performed with rainfall,weather station,water vapor and vertical motion.The results show that the two processes were influenced by Chuan-Dian shear line,and there are some favorable conditions in the water vapor transportation and vertical motion.In the former process there is a high-level trough in 500 hPa.In the latter process there is a convergence between two hights in 500 hPa,and water vapor convergence and ascending motion are stronger than the former process,therefore supported by all kinds of favorable conditions,the rainfall in the latter process is stronger than the former process.