Abstract: A regional climate model (Reg CM4) is used to simulated the winter congeal process which occurred in the beginning of 2008 (13 th Jan. to 14 th Feb.) in Guizhou, by comparing reanalysis data with the NCEP / NCAR. The results show that the model has certain performance to simulate the cold air path, the inversion layer and the lower flow field, especially the vertical distribution of the inversion layer. The simulated results of the horizontal distribution and vertical structure of average temperature are consistent with the result of reanalysis data, which are able to effectively describe the horizontal distribution pattern of the temperature, which is negative in north and positive in south. Especially, the simulated results can simulate the path, the central intensity, the location and extent of the cold air in northwest. The vertical structure of average temperature is able to describe the whole processes of inversion layer, including the formation in the early stage, the maintenance in the medium stage and the disappearance in the later stage, which the time node simulation is more accurate in particular. The simulated results of the lower flow field over Guizhou fit well with the result of reanalysis data that show the invaded strong cold air from high latitude from northeast, which merges with the warm and moist air from tropical ocean in west Guizhou during the congeal process. The simulation result of the north-south thermal frontal zone has deviation to the north and east from the distribution of reanalysis data, might concerned with the simulation of relatively large southwest low-level wind.