Abstract: By using NCEP global 1°×1° re-analysis data and 2.5°×2.5° mean re-analysisdata,ananalysis is made on 12 severe freezing rain events with blocking pattern in Guizhou. The results are as follows. (1) The severe freezing rain is relates to blocking circulation in mid-high latitude over Asia and Europe.Frontal zone in low latitude is favorable for establishment and maintenance of low-level southwest jet offering vapor forf reezing raino ccurrence and development.The cold air is strong and sustained on the ground.(2)The southwest jet is significant at 700 hPa,which provides warm moist vapor and makes the warming effect strong at the top of the temperature inversion.(3)A cold flow covers minimum altitude and the ground.The freezing rain occurs against the background of aquasi-stationary front which is related to high humidity area with the relative humidity higher than 70 %. The quasi-stationary frontal cloud system in Guizhou is characterized by warm-humid cloud on the front and could-humid cloud under the front.(4)In the period of severe freezing rain,the gradient value of inversion in the lower and middle troposphere increases,and maximum gradient value is over 8-10 ℃.