Based on the meteorological observations and Doppler radar data, an analysis of a snow event at Qingdao City from 17 to 18, February, 2005 is made. It shows that the low-level warm advection, the vertical wind shear and the high-level jet provided favorable dynamic conditions for the event, the middle-level southwest air flow and the surface layer moisture from the Huanghai Sea and Bohai Sea provided the moisture conditions for the event. The intensity of the snowfall enhanced rapidly to the heaviest, as a meso-cyclone appeared over Qingdao at the 2.0—2.7km layer. And then, as the cyclonic wind field broke, the snowfall became weaker. The initial echo appeared at the 3.0—3.5km layer, and then, it extended downward and upward.