From the night of 20 to 22 in Dec. 2004, a heavy snow event occurred in Huanghuai basin. The event is analyzed with Doppler radar data and simulated with mesoscale numeric model. It shows that the generation and characteristics of heavy snow was definitely different from that of heavy rain in Meiyu front. The characteristics of the heavy snow could be well described with Doppler radar data: the average convective height was 3—4km, the maximal height less than 8km. When the snow was heavy, a very strong low-level jet was found. It was ENE, 12—14m·s^-1, near surface, at 925hPa. The vertical shear between upper level and low level was obvious. The baroclinicity was very strong. The evolution and characteristics of this event could be well simulated with high resolution mesoscale numeric model.