Abstract:The Meiyu torrential rain rainstorm took place on 29 June 2009 in Hubei Province is analyzed by applying intensive meteorological radiosonde data, reanalysis data from NCEP, and precipitation data of automatic meteorological stations in Hubei Province. The results show that during the heavy rain, there existed a long quasi zonal Jianghuai shear at 700 hPa; the north frontier of the low level jet stream at 850 hPa moved to the northern Jiangnan. The 〖WTBX〗θ〖WTBZ〗se front at the northwestern Hubei Province moved southward and enhanced slowly, and the rainstorm region was to the south of the〖WTBX〗 θ〖WTBZ〗se front, where the local change of〖WTBX〗 θ〖WTBZ〗se was always positive though the change amount was little. The convergence of vertically integrated moisture flux occurred before the heavy rain, and the convergence area was in accord with the location of the rainstorm. In both Enshi and Wuhan radiosonde stations, besides the large scale low level shear line, the occurrence of heavy rainfall was influenced by the local meteorological elements, especially plenty of water vapor at low levels, which was a necessary condition for heavy rainfall. The rainfall became severer after the high level trough passing Enshi and the vertical shear of horizontal wind between middle and high levels appearing. The descending dry air at high or middle levels was a good condition for heavy rainfall at Wuhan for unstable stratification was intensified accordingly. The abrupt increase of rainfall coincided with the southward passing of the horizontal wind shear at low levels.