In this study, the Rift Valley Fever virus attenuated vacdne was used after addition of skimmed milk as stabilizer with different concentrations (10%, 15% and 20%). After lyophylization, it was found that there was no difference between all the concentrations except that 15% and 20% had no good physical appearance; 10% concentration was chosen to continue this study. Regarding the titration and evaluation of the prepared vaccine, it was noticed that the dire was 10⁷⁴ Tao_s° /ml. It was found sterile and safe in hamster and sheep. The potency test in tissue culture was 10⁷⁴ TODso and the mean SNT of sheep sera was 80. The titre at room temperature was 10" TCIO 50 / ml on 1st day and readied 10⁷⁴ TCIDso /ml on 7th day, while in 4°C the litre was 10" TC2135₀ /ml in 1st month reaching to 10" TC1050 / ml in 12th month, while, in -20°C the titre was not changed up till 9th month and reached 10" TCID50 /ml at 12th month. By estimating the level of antibodies of the prepared vaccine, it was high up till the end of the experiment (6th month) with an average of 3.18 NI by using serum neutralization test. From this study, it is dear that 10% skimmed milk is the best concentration stabilizer of choice, the prepared attenuated vaccine and being suitable for use when stored at room temperature for 48 hours and 6 months at 4 °C. It can be stored at -20 °C without loss in its titre till 9 months.