Abstract: Specific antigens are detected in cyst fluid and cyst wall of Echinococcus granulosus, as well as germinal cells cultivated in vitro by sodium dodecyl sulphate polyacrylamide gel elec-trophoresis (SDS-PAGE) and enzyme linked immunotransfer blot technique (ELIB), using the sera from mice infected with protoscoleces of E. granulosus for at least 10 months. A specific reaction band of 52 kDa or 38 kDa was detected in soluble protein of germinal cells and cyst fluid, respectively, but these two reaction bands were present concurrently in the cyst wall. The sera from 7 normal controls, 7 hydatidosis patients and 3 cysticercosis patients were used to study the specific antigen from the germinal cells. The results noted that the reaction band of 52 kDa was seen in all the sera from hydatidosis patients, while the sera from normal human controls and cysticercosis patients showed no reaction band.