Based on conventional surface and sounding observation data, NCEP 1°×1° reanalysis data, a snowstorm structure with low-level eastern wind in Shanxi Province from 28 to 29 November 2011 is researched. The results are following: (1) This weather process is developed by the joint influence of upper westerly trough, shear lines in lower level, ground return-flow and inverse trough. The northeaster wind occurs from 925 hPa to 850 hPa upper Shanxi about 18 h before the snowstorm, the northeaster wind occurs on surface in Shanxi about 12 h before the snowstorm, and it is strong during the snowstorm; The low-level northeaster wind is cold and dry before the snow, and it is a wet-cold pad during the snow. (2) The water vapor of this snowstorm comes from the southwest water vapor emerging in southuest China and transport northward, this emerging southwest flow comes from the southwest wind in the front of South Westerly Trough and the turning of east flow in Beibu Gulf which comes from Western Pacific, then it is combined with the southwest flow in the front of the westerly trough. The heavy snow occurs in the area of south wind of the wind convergence on 700 hPa where is on the northwest of the vapor flux center and has dense isolines. (3) The heavy snow accompanies with the deep wet layer, the obvious vapor flux convergence under 500 hPa and strong updraft current upper 800 hPa in the troposphere upper Shanxi area, under 800 hPa it has obvious downdraft current which is caused by the low-level eastern wind. (4) The westerly jet on 300 hPa moves eastward and goes down southward among the heavy snow, Shanxi is located on the right of the jet's entrance region and occurs strong divergence, which impels the development and maintenance of the inverse trough of the Great Bend of the Yellow River on surface, and may cause stronger updraft current in the area of heavy snow.