Ultrastructural characteristics of hemocytic differentiation pathway in Sericinus montetla Grey were observed with transmission electron microscope. Hemocytic differentiation took place in loose islets of hemopoietic organs as indicated by the presence of differentiating hemocytes; prohemocytes, plasmatocytes, granular cells and spherule cells. They are differentiatied from the stem cells through individual cell lineages. However, differentiating aspects of the oenocytoids were not observed. According to Brehelin and Zachary (1986), the premature hemocytes around the hemopoietic organs were classified into five types; prohemocytes, plasmatocytes, granular cells, spherule cells and oenocytoids.