Abstract: Rift Valley Fever (RVF) is an acute infectious zoonotic arthopod - born viral disease, affecting many species of animals and it causes great economic losses in animal wealth and transmited to human and has zoonotic implication. Vaccination of susceptible animals with RVF vaccines are the important factor for controlling the disease. This study was applied to improve the ordinary vaccine by using Montanide gel 01as adjuvant with comparing the results with the Aluminiumhydroxyde inactivated RVF vaccine, through evaluating the humeral and cellular immune response and duration of immunity in sheep vaccinanted with the prepared vaccines. the antibody titre in the group vaccinated with montanide gel inactivated RVF vaccine reached the protective level at the 7th day post vaccinatin and stay within the proteceive level till the end of the 11th month in the group vaccinated with one dose of montanide gel inactivated RVF vaccine and till the end of 12th month in sheep vaccinated with the same vaccine. These results revealed that the best vaccine is 20% montanide gel inactivated RVF vaccine when used as two doses which gave higher level of antibody all over the period of the test compared with that of other vaccinated groups. Also the results of cell mediated immune response showed that: (i) The cell proliferation expressed by optical density showed early significance in sheep vaccinated by montanide gel inactivated RVF vaccine and slight elevation in sheep vaccinated by aluminium hydroxide gel inactivated RVF vaccine.