Using the conventional, automatic, satellite, and radar data, a comprehensive analysis is conducted of the heavy rain occurred on 19 September 2010 in the middle Shanxi. The results show:(1) The subtropical high at 500 hPa, which changed from block pattern to zonal pattern, was strong, and the horizontal anticyclone at 200 hPa maintained stably, which were important background factors for the formation and maintenance of the horizontal shear line at lower levels. The vortex and horizontal shear line were mainly influencing systems. (2) There were typical β meso scale characteristics in precipitation. A convective cloud mass first occurred in the west side of the vortex; with the strengthening of SW flow before the vortex, the convective cloud mass promptly developed and moved to east; and the heavy rain was caused by the β meso scale convective cloud mass triggered the shear line. 〖JP2〗Opposite correlation was found between TBB and rainfall in future 6 hours. (3) There was a line shaped echo band in radar, and the heavy rain was located at the area of over 45 dBz. (4) There existed cold advection in the northwest of vortex, which enhanced the vortex, and there existed positive vortex advection at 500 hPa, which were the dynamical factors for the maintenance and development of the horizontal shear line that induced the heavy rain.