Abstract: The paper aims to study the cause of snowstorm in Inner Mongolia. With conventional observation data and NCEP reanalysis data, the author adopted Grads graphics software and Micaps3.2 system to analyze the synoptic characteristics of a blowing snow process during 2013 in the eastern region of Inner Mongolia. The results showed that: the upper trough that moved to southeast strengthening cold vortex provided favorable large scale circulation for blowing snow weather, the principal impact system of this blowing snow was Mongolian cyclone and Mongolian cold high. The strong high-level jet played an important role in this process. On the one hand, divergence suction on its left front of exit area was so powerful that ground Mongolia cyclone developed strongly, it was conducive to produce snow. On the other hand, the convergence zone on the left of the entrance formed a descending motion, and the momentum passed downward provided favorable conditions for the formation of surface winds. Divergence and vertical field all formed a secondary vertical circulation, its convergence ascending branch provided impetus lifting conditions for snow, and its sinking branch passed down high altitude momentum to the ground, making increased surface wind speed. The existence of a southwest low-level jet in this process continually transported the warm air in low latitude to the eastern of Inner Mongolia, and played an important role for the formation of snow weather.