We had reported that it is always observed a small body resembling a platelet in urine of normal and various sick persons and the small body is a platelet itself or a ruin of platelet (Lancet, 1, 1339, 1975., N. Engl. J. Med., 293, 44, 1975., Nihon Univ. J. Med., 17, 117, 1975., Japan. J. Clin. Hemat., 17, 632, 1976., Jap. J. Urol., 67, 903, 1976.). We had studied the Platelet-like bodies in urine of 3 cases suffered from ITP, 3 cases suffered from AML, 2 cases suffered from CML, and one case suffered from MOL, SLE and reticulosarcoma, respectively. The small bodies were also observed in all urine of these patients. By transmission electron microscopy, these small bodies were a platelet itself or a ruin of platelet. And the TEM findings showed differencein each blood disorder and treatment.