Based on precipitation and temperature data of 21 stations in January in Ningxia region,  NCEP / NCAR monthly height and wind grid data of 2.5 × 2.5 °over Northern Hemisphere from 1961 to 2008, and NCEP Eurasian snow cover data from 1973 to 2007, the formation mechanism of the extremely cold and snowy weather event accurred in January 2008 in Ningxia region was analyzed. Results show that the anomalous atmospheric circulation was one of the most important causes. La Nina event and Eurasian snow cover anomalies resulted in atmospheric circulation anomaly, then anomalous precipitation occurred in January in Ningxia.

The dates of the first soaking rainfalls in the south and middle parts of Ningxia were forecasted statistically by using the optimal subset regression method, the forecast equation was set up and it king rainfall in the regions in recent 30 years was discussed in detail effect was analyzed, and the(hange of the dates of the first soarainfall is 23.3% in April, 23.3% in May, and 33 Results show 3 %  in .Tune that the occurrence in Yinc;huan region
probability of the first soaking ，during the last 30 years the dates of the first dates of the first Apri1,20% and tinn fnr the dates   in March, 20% soaking rainfalls were later in 1970x, earlier in 1980x, and medium in 1990s between that in 1970s and 1980x.  The soaking rainfall(onc;entrated relatively in southern mountain areas of Ningxia, the probability of o<(urrenc;e is 53% in 17% in May and Marc;h,and only 10% in June, and it is found that there is a slight trend of postponing with fluc;tuaof the first soaking rainfalls in this region in recent 30 years. The effect of forecast using the optimal subset regression method for the date of the first soaking rainfall is good in  Ningxia