A severe snowstorm occurred between 9 and 12 November 2009 in Shanxi Province, which was the strongest snowstorm since meteorological records began. The snowfall in most parts of the province was in the range of 10 to 66 mm, and that at 86 counties (cities) reached the maximum for the same period in history. Both upperand lowerlevel meteorological observation data and satellite images were used in the comprehensive analysis of the process. The results show: the strong southwest flow at upper levels, the northeast air at lower levels, and the returnflow on the surface provided jointly a favorable circulation condition for this snowstorm. The 500 hPa trough and 700 hPa shear line were the major influencing systems. The continued moisture convergence from the lowlevel jet provided sufficient water vapor. In satellite images, the lowvalue areas with TBB being lower than -50 ℃ and the heavy snow fall areas had a good correspondence relationship.