Fractionation of fertile Hydatid cyst fluid antigens (FHCFA) revealed 12 protein fractions at molecular weights (MW) of 105, 79, 62, 49, 38 28 24 21, 18, 8 and 2 kD bands over 105 kD. The bands at MW of 38, 36, 29 18, 16, 12 and 8 kD were reacted specifically with sera of Hydatid Crabbits as well as sera of surgically proved HCinfected patients using enzyme linked immuno-transfer blot (EITB) technique. Evaluating the diagnostic efficacy of 3 eluted concentrated sub units of these antigens at MW range of 32-38, 16-18 and 8-12 kD, revealed that the fractions in the range of 8-12 kD appear as the most specific (96.66%) fractions. It didn`t cross reacted with anti bodies (Ab) in sera of patients infected by Fasciola, gastro-intestinal nematodes (G. I. N.) infected camel as well as Fasciola and Moneizia infected sheep. It clear mild level of cross reaction (10%) with Virus hepatitis C and Schistosoma manson infected patients sera. These fractions appear more sensitive (100%) for diagnosis of anti HC Ab in sera of surgically proved HC infected patients, HC infected camels and HC experimentally infected rabbits using ELISA technique. Fertile Hydatid cyst fluid antigen (FHCFA) of 32-38 kD appear less specific (93.33%) than the fraction of (8-12 kD), but this fraction still has absolute sensitivity (100%). The last groups of bands (16-18 kD) appear as the lowest specific (81.66%) and sensitive (92.0%) one. The protein fractions in the range of 8-12 kD showing marked diagnostic efficacy for hydatidosis infection in random samples of exposed people and pre-slaughtered animals. Diagnosis of infection by ELISA technique was closely related to diagnosis using sonographic examination in human and post mortem examination in animals. So that the former group of antigens identified as a good tool for diagnosis of the disease in human and investigation to infection status in living animals, the matter which is essential to improve the prognosis of the infected patients and breeding valuable animals.