The hemocytes of Macrobrachium rosenbergii and Procambarus clarkii were studied. Three kinds of blood cells,the hyline hemocytes, the semi-granular hemocytes and granular hemocytes were distinguished according to the N/P ration ofcells, the distribution and size of granules. The numbers of the hemocytes of Macrobrachium rosenbergii and Procambarus clarkii were 1.02±0.21×10⁷ Ind·ml^-1 0.85±0.15×10⁷ Ind·ml^-1, respectively.The hemocytes of the two shrimp weresignificantly different in granules. The staistics show that the hyline hemocytes, the semi-granular hemocytes and granularhemocytes of the Macrobrachium rosenbergii were 21.3±6.3%, 45.7±2.5%, 3.0±6.8% in the total amount of blood cells. Thepercentage of these cells of Procambarus clarkii were 12.0±5.8%, 49.5±5.1%, 38.5±9.5%, respectively.The hemocytes of threekinds were significantly different in N/P ration and size of the same species shrimp.