Six types of hemocytes were identified in adult grasshopper, Euprepocnemis shirakii Bolivar. The morphological and ultrastructural characteristics of these cells were characterized by phase contrast, scanning and transmission electron microscope. The prohemocytes are small and spherical cells with large nucleus. The plasmatocytes are spindle shaped or polymorphic cells which show numerous cytoplasmic processes on the cell surface and they have lysosomes and vesicles that may be involved in phagocytic function. Especially, multivesicular bodies are observed in the polymorphic cells. The granulocytes I are spherical shaped cells. They are characterized by a number of electron dense granules measuring $0.2-0.3{mu}m$ in average diameter and marginal band of microtubules which are always in close proximity to the cell membrane. The granulocytes II are oval or spindle-shaped cells. They contain large electron dense granules measuring $0.5-0.8{mu}m$ in average diameter. Their cytoplasm is filled with numerous granules. The spherulocytes contain large amounts of spherules that most of their cytoplasm. Spherules filled with fine granules or flocculent materials. The oenocytoids are large spherical cells with few cytoplasmic organelles. Their cytoplasm contains peculiar aspect of motochondria and numerous polyrobosome.