Inactivated IBR vaccines were prepared using montanide ISA 25, 50 and 206. Purity, safety and sterility of the prepared vaccines were ensured then their potency was evaluated in vaccinated calves using SNT. Humoral immune responses to the prepared vaccines were evaluated in calves after two doses with two weeks intervals. Protective serum neutralizing antibody titer started at 3 weeks post vaccination for both montanide ISA 25 and ISA 50 adjuvant IBR vaccines but started at 2nd week post vaccination for montanide ISA 206 adjuvant IBR vaccine. These protective serum neutralizing antibody titers persisted to 24, 32 and 36 weeks post vaccination for montanide ISA 25, 50 and 206 adjuvant IBR vaccines, respectively. It was concluded that IBR vaccine adjuvant with Montanide ISA 206 gave the earliest and longer duration protective neutralizing antibody titer.