Sarcocystis species are widespread in cattle throughout the world. Some species are pathogenic and have medical importance. In the present 235 Assiut Vet. Med. J. Vol. 52 No. 109 April 2006 work, one hundred sample from ocular muscles of cattle were examined where the infection rate was 89%. Ultra-structure studies of Sarcocystis species of cattle with transmission electron microscope revealed the presence of four species. The first species was Sarcocystis hominis with cylindrical (finger like) villar protrusions perpendicular on the cyst surface with broad bases. The second species was Sarcocystis hirsuta that showed club or bulb like villar protrusions with constricted base and tapered tips. Some of villar tips folded to form conical projections. The third one was Sarcocystis cruzi which was characterized by thin wall with hair like villar protrusions folded over the surface of the cyst and approximately parallel to the cyst surface. The fourth species was Sarcocystis fusiformis like cyst which had highly branched villar protrusions with constricted base. This is the first description of this species in cattle also it is the first time of description of Sarcocystis hominis in ocular muscles in Assiut.