The spatiotemporal distribution of freezing rain in Beijing is analyzed by using the surface observation data and sounding data from 1 January 1955 to 30 April 2013. The temperaturehumidity structure and the formation mechanism type of freezing rain are studied using the sounding data. Comparative analysis of the temperaturehumidity structure and its difference from freezing rain, rainfall, sleet and snow is done using the observation data collected from November to April in 2000-2013. The results show that freezing rain is prone to occur in the northeast and southeast of Beijing, from November to the next April, of which about 86.4% is warmrain mechanism. The temperature stratification curve under 850 hPa is nearly in vertical and the temperature is below 0℃, which is the main characteristics of Beijing regional freezing rain. The main difference between sleet and freezing rain is the temperature under 850 hPa, the temperature of sleet is higher than the freezing rain.