Global warming has become an important issue in many industrial applications: Power generation, refrigeration, cement production, etc.. Hence, there is an obligation to reduce energy consumption, losses and environmental impact. This work is dealing with the improvement of a vapor compression cycle. Impo irreversibilities The isenthalpic expansion valve was replaced by an isentropic expansion two phase ejector in order to increase the refrigeration efficiency. The results of the expansion valve vapor compression cycle exergy analysis has pointed the components where exergy destruction occurs. The exergy destruction is less important in the expansion valve than in the condenser but the kinetic energy recovery potential is interesting. The comparative exergy analyses of the expansion valve versus ejector cooling cycle for R22 and R717 refrigerants, show improvements of the COP and exergy efficiency while reducing compression work, heat rejection at condenser.