the herein study was devoted to overcome the obstacles dealing with the utilization of the live attenuated Bovine Ephemeral Fever (BEF) vaccine viz, the cold chain and the undesirable post-vaccinal reaction. Methylglucoside-sucrose (MS) was proved to be an excellent stabilizer for BEF thermostable vaccine. The permissible titer of the lyophilized MS-BEF thermostable vaccine was achieved even after 6 months at 25°C, 3 months at 37°C and 20 days at 45°C. The study revealed that freeze-dried MS-BEF thermostable vaccine was reconstituted with saponine (0.2μg/dose) as inactivator just at the time of inoculation. Such investigations were carried out on 4 groups of calves each was consisted of three animals. The first group of animals were inoculated with the MS-BEF thermostable vaccine kept at 25°C for 6 months. The second groups were inoculated with the forementioned vaccine kept at 37°C for 3 months. The third group of animals were vaccinated with BEF vaccine kept at 45 for 20 days. (The vaccine titer was 105.5 TCID50/ml in the three above mentioned groups), whereas the fourth group was kept as nonvaccinated normal controls. The three animal groups received booster dose at two weeks of post-first vaccination. It has been deduced that such vaccine effectively induced high mean BEF neutralizing antibody titers post- boostering vaccination and protected cattle for one year. Thus, MS stabilizer was recommended for the preparation of thermostable live BEF vaccine inactivated at the spot with saponine.