The two-dimensional image data of ice and snow particles and the shape features of snow particles and the shape features of snow particles from the measurements of 13 flights equipped with the particle Measuring System (PMS) during 1991-1993 are analyzed,with the focus on the occurrence frequency and the size distribution of graupel particles. Based on certain assumptions,the accumlated super cooled water content in the clouds above the oberservational level is estimated according to the diameters of graupel particles,so as to find out the potential of artificial precipitation above the operating level. The primary results indicate that graupel particles were found in .the operating processes of many flights of different durations; the estimated maximum integrated supercooled water content is 130 g/m². It can be seen from the duration percentages of graupels in the processes of the flights that supercooled water is distributed horizontally and the graupel particle percentage varies greatly in different flight. In addtion,the comparison of the data obtained in the same flight indicates that the higher the altitude and the temperature,the lower graupel particle percentage is observed.