Abstract: This paper deals with the evaluation of the performance of a refrigeration system by using different refrigerant mixtures. This refrigeration system works under vapour compression cycle with the basic principle "" The liquid when evaporates absorbs heat"". The refrigerant continues changing from liquid to vapour state when absorbing heat and from vapour to liquid when giving out heat. The refrigerants used in the system are R134a (Tetrafluoroethane), R290 (Isobutane) and Blend of Tetrafluoroethane and Propane (R134a and R290). This project deals with a comparison study of the performance of different refrigerant mixtures mentioned below with R134a kept as a comparison parameter. The above refrigerants are mixed based on weight proportions in different ratios, and their following mixtures used are: