Abstract: To better study microphysical characteristics during snowfall process in low latitude plateau area,drop size spectra were collected with Parsivel2 raindrop spectrum detector during the snowfall events in 16—17 December 2015 in center of Yunnan Province,the evolution characteristic of the microphysical parameters,particle number concentration,particle size and velocity distributions were investigated.It was found that:snowfall dominated in the whole snowfall process,the quality-weighted average particle diameter was 0.82mm in pure rain period,the quality-weighted average particle diameter was only 0.79mm in pure snow period,the average diameter of snow particle was less than which of rain particle.The precipitation intensity,number concentration and the radar reflectivity factor had positive linear correlations,particle number concentration was larger when the radar reflectivity and the precipitation intensity increased larger,particle diameter had no obvious positive correlation with rainfall intensity characteristics.The drop speed of particles for different phases of particles in the same diameter had significant differences.The drop speed of rain particle had linear correlation with particle diameter for rain particles and which was closed to the curves of frosting and within the particle diameter range of 1.6mm,but the drop speed of snow particle was closed to the curves of no-frosting and which had no correlation with particle diameter.The diameter of rain particle was larger and the drop speed was faster,and the rain particle showed the significant attachment characteristic of frozen drops,but snow particle showed the main single ice-crystal growth characteristic.