The characteristics of a severe weather of glaze icing are of the long maintenance of time and of the supercooling rainfall.By using 56 sounding and upper-wind data,the macro thermal and dynamical characteristics of cloud layer over the central part of Guizhou plateau were analysed.It was found that the cloud depth,the existence of warm(T>0℃) layer and the turbulence intensity in mid-upper cloud layer have great influence on supercooling rainfall.The synoptic system and the large scale circulation conditions for long maintenance were also discussed.