Abstract: The process of a snowstorm from April 1stto 2nd2016 in Hulun Buir City of Inner Mongolia was analyzed by using conventional observational data, Micaps data and precipitation data. The results showed that the establishment of Ural Mountains′high-pressure ridge and Okhotsk blocking high rendered the favorable circulation background condition for the transformation of Lake Baikal cold vortex from low trough; the cold vortex and frontal cyclone were identified as the main effect systems of the snowstorm process in Hulun Buir City; low-level jet provided abundant water vapor conditions for the snowstorm; the left side of upper-level jet exit regions and the left side of low-level jet output regions were observed to overlap and couple with each other,which formed a strong dynamic upward-effect, and accordingly the snowstorm was triggered.