In the present study, two cell inactivated vaccines were prepared from the local and Australian strains of BEF virus. Each vaccine was inoculated in a group of susceptible cattle using the some dose and giving a booster dose two weeks after the initial dose. It was found that cattle responded better to the local strain vaccine than to the Australian one recorded higher levels of serum neutralizing antibodies suggesting a longer period of protection. The prepared hyperimmune sera; in rabbits and conjugated with Fluoresce in Isothiocyanate (FITC) showed antibodies similar in their titer behavior to those in vaccinated cattle i.e. the local strain induced higher antibody titer than the Australian one. It was clear that the Flu resent antibody technique "FAT" is a rapid and sensitive technique to diagnosis BEF using either conjugated antiserum.