Horizontal observations, were made of the clouds over tne area ot Daxinganling forestfires on May 24, 1987, using airborne PMS probes. The analysis shows that (1) the ice crystals(25-800 μm)a,nd precipitation paticles (200-6400μm) from space and the the regions for space-dendrites forming appear with their higher concentrations, comparing to those from the regions with dendrites and stells,(2)the sowfall with space-dendrites shows the highest indensity among the various precipitation particles.