Fascioliasis is a disease of human and grass-grazing animals caused by the parasitic worm Fasciola spp; which lives in the bile ducts and cause liver cirrhosis. It is generally agreed that facsioliasis caused heavy economic loss in liverstock throughout the world. Clinically, fascioliasis may be falsely diagnosed asamoebic hepatitis, acute infective hepatitis as well as disorders associated with cirrhosis and primary carcinoma of the liver. Several tests using different fasciolal antigenic preparation, including partially purified antigen and excretory-secretory (ES) products of the adult worm, have been reported for the immunodiagnosis of fascioliasis. To enhance the specificity of immunodiagnosis of fascioliasis, attempts were directed to assay the fasciolal circulating antigen which can be detected in sera obtained from infected specimens as early as the third week after infection. The immunodiagnostic method can provide an accurate tool for diagnosis as well as the assesment of cure of fascioliasis.ES antigenic preparation from adult worms of F. gigantica express a dominant and immunogenic epitope of 15.8 kDa. This epitope demonstrated a strong immunogenic properties in both