Refrigerator is a household appliance used to preserve the foods, vegetables, beverages at low temperature. Refrigerant is the blood of the refrigerator and it changes its phase to transfer heat for giving cooling effect inside the refrigerator. Generally many refrigerator works under the vapour compression cycle and it uses only one refrigerant. Each and every refrigerant used in the refrigerator must have disadvantages, to overcome this problem we use mixed refrigerant (two different refrigerants with different properties are mixed together). In this project combination of R600a (isobutane) and R134a (1, 1, 1, 2-tetrafluroethane) is selected as a mixed refrigerant. R600a have some good properties like zero ODP, zero GWP and high latent heat of vapourization and R134a is non-toxic, non-flammable, non-corrosive and zero ODP.