Abstract: A snowstorm was well recorded on November 29,2019 in Zhangjiakou and the snow drop spectrum characteristics of this weather was analyzed based on OTT Parsivel （Particle Size and Velocity Spectrometer） data and intensive observations.This snowstorm was categorized into four stages,including the beginning stage,snowflake stage,stable snowfall stage and the ending stage.The results are as follows:（1） In general,the evolution trend for all microphysical parameters （rainfall intensity R,number concentration N_t,rainfall content W,radar reflectivity factor Z,mass weighted average diameter D_m） is nearly identical during the whole snowfall process.In the snowflake stage,precipitation intensity,rainfall content and radar reflectivity factor are all greatly affected by particle number concentration.However,in the rest snowfall process,the particle diameter takes the responsibility for those changes above.（2） During the stable heavy snowfall stage,the particle number concentration （N_t）varies from 10 3 to 10~4,but the D_mis less than 1 mm,which may be caused by the shattering of falling large snowflakes under the circumstance of low temperature.In the process of snowfall,90% particles were falling at a rate of less than 2 m/s,while at the stable snowfall stage the falling velocity of snow particles was mostly ranging around 1-1.5 m/s.（3） The second,third,fourth moment and the least square method were both used to fit the Gamma distribution of the particle spectrum distribution in different snowfall stages.In the process of snowfall,the least square method has better fitting results than the second,third,fourth moment.