Abstract: Under the same testing condition and using the water as disperse medium,the particle size and its distribution of the three kinds of jargonia catalyst powder samples were determined by means of the laser particle size analyzer. The particle size and its distribution of the three samples were compared. The particle size of the No.2 sample was the smallest and the particle size distribution was concentrated. The No.1 sample was seondary. The particle size of the No.3 sample was the largest and the particle size distribution was dispersed.