The performances of a refrigeration cycle of a 1, 1-difluoroethane/pentafluoroethane (HFC152a/HFC125) mixture used as a refrigerant for domestic refrigerators were calculated and analyzed in detail. The results of the theoretical analysis indicate that the HFC152a/HFC125 mixture in the composition of 0.85 mass fraction of HFC152a has a similar refrigeration performance with the existing refrigerant CFC12. Experimental research on the main refrigeration performances of domestic refrigerators was conducted, under the different proportions and charge amounts, when HFC125a/HFC125 is used to substitute CFC12 as a "drop-in" refrigerant. The experimental results indicate that the refrigeration performances of the domestic refrigerator charged with the new refrigerant can meet the requirement of the National Standard of China, under the appropriate proportion and the optimum charge amount. In conclusion, the mixing refrigerant HFC152a/HFC125 proposed in this study seems to be an appropriate long term candidate to replace CFC12 as a new generation refrigerant of domestic refrigerators, because of its well environmentally acceptable properties and its favorable refrigeration performances.