Abstract:The sperm-iogensis of Echinococcus granulosus was observed on the ultrastructural level by transmission electron microscopy. The development and the morphological characteristics of spermatogonia, spermatocyte,sprmatid and sperm were studied. The results showed that the sperm of Echinococcus granulosus was composed of microtubes which were arranged and combined many times in spermatid mainly. The mitochondria and the acrosomal structure hadn't been found in spermatid and sperm.The mature sperm of Echinococcus granulosus was composed of head and tail.The head is light colour and it's top was wrapped up by a cap-shape materia1 which was composed of many light and dark band which was arranged at an angle of 30°to the axial filaments. The structure of a whole sperrn was consist of an axial filament and it's intrinsic membrane. The axial filament extemded to head and tailof sperm. A great many of microtubes was arranged on the inner edge of the intrinsic membrane,two layer microtube were arranged at one side on the "2 ×4+ 1 "structure and one layer at another side,only one layer microtube closely adhere to the inner edge of the whole intrinsic membrane of the behind part of tail. The axial filament was composed of on central microtube and nine pairs of outer microtubes. The central microtube surrounded by a fibrous sheath whlch were connected with nine pairs of outer microtubes by fibrous filament.