The first snow in North China during 6—7 Nov. 2003 is simulated by the GRAPES global numerical model developed by the Chinese Academy of Meteorological Sciences. The analysis of the output data indicates that GRAPES model can simulate out circulation's evolution og high and low level and the main synoptic systems,beside the distribution of psecipitation areas and the precipitation cells. The effect of simulation inserted cloud data is better than not inserted. But precipitation areas above 25mm are boti too large. The model can provide correct and high resolution data of diagnostic analysis also.