By using the 55 a data, the snowstorm in Wuhan during 1951—2005 were analyzed. The results suggested that the frequency of which snow depth is greater than 5 cm in Wuhan is about two days a year, mainly in January , the next were February and then December. Conditions of atmospheric stratification is the key to producing snow. The chief weather systems which contribute to the snowstorm were ground cold air, the lower and middle southwest jet in the south of Changjiang River and westerly trough of 500hPa. The southwest jet of 700 hPa in the south of Changjiang River is related to the intensity of snowstorm. The path and intensity of ground cold air affect the degree of temperature decrease. According to the numerical weather forecast (EC), four requirements must be met for a snowstorm in Wuhan. Firstly, southwest jet in the south of Changjiang River is over 16m/s at 700 hPa. Secondly, the difference of geopotential height at 500 hPa between Wuhan and Chengdu is over 50 gpm. Thirdly, the temperature of Wuhan less then 0℃ in 850hPa temperature field, and a temperature inversion is present from 850 hPa to 700 hPa. Fourthly, there is cold high over 1045hPa from Mongolia or north of China and the pressure of Wuhan increased obviously to 1 025 hPa or so.