Based on Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations(CALIPSO)Lidar level 2 aerosol data derived from the period of 2007—2014,in this study,the vertical distribution characteristics of aerosols observed in a haze event over North China and during December 2013 are analyzed.The results revealed that the aerosol extinction coefficients(σ) exponentially declinedwith altitudes.The annual mean of aerosol scale height is 2.48 km.Under 1 km,there isa layer of high σ value with the annual mean of 0.333 km^-1,representing maximum annual mean value in Winter and minimum one in Spring.The annual mean Particle Depolarization Ratio(PDR) shows an increase with the altitude,varying from 0.18 to 0.25.It is noteworthy that PDR ration is large in Spring,while it is small in Winter.The annual mean Color Ratio(CR) ranges from 0.7 to 0.8,gradually increasing with the altitude.In addition,CR shows declining the vertical distribution in Spring,while the trend inclines in other seasons.The polluted dust is the major aerosol type in the lower atmosphere.In Spring,the major aerosol type is dust,while the polluted dust is dominant in Summer and Autumn.In winter season,the major aerosol type is dust in middle and upper atmosphere,while the polluted dust is in lower layer.During a haze period,a homogeneous mixing layer with high σ exists below1 km.It shows that its value is three times of σ in a haze day in comparison with a clean day.Accordingly,the values of PDR and CR for the haze day are lower than those values in the clean day.Under 2 km,most of PDRs are below 0.2,and CRs are between 0.3 and 0.5.The polluted dust,which is the mixture of the remote transported dust and the local smoke particle,is the major aerosol type during a haze event.