Abstract:By using NCEP/NCAR reanalysis data and daily precipitation data from 44 stations in Jianghuai region during Meiyu season (June 16-July 15) from 1980 to 2010, the distribution of Meiyu precipitation over Jianghuai region and its relation with East Asia subtropical westerly jet was studied. Results show that the first pattern is "south-positive (negative) and north-negative (positive)", which is influenced by the location of the westerly jet. When the jet is abnormally southward (northward), the rainbands locate over the south (north) of Jianghuai region. The second pattern is "middle-negative (positive) and sides-positive (negative)", which is influenced by the intensity of westerly jet. While the jet is abnormally weak (strong), the rainbands occur in the northwest and southeast (center) of Jianghuai region. Synthetic analysis shows that, for an abnormally southerly jet location, the 500 hPa subtropical high is weaker and the location is far southward, 850 hPa has a convergence zone for water vapor and wind field over Jianghuai region, which can easily lead to the distribution of the "south-positive and north-negative" type. When the intensity is abnormally weak, from the central and eastern Jianghuai region to the southern Japan, 500 hPa has no obvious vertical motion, water and wind field diverge at 850 hPa, which favor the formation of "middle-negative and sides-positive" type.