Abstract: At present, the working fluid R22 is often used in refrigeration and heat pump systems, but it will be replaced in the next several years because its ozone-depletion potential (ODP) and global-warming potential (GWP) are very high.In order to seek some novel working fluids to replace the R22, some experiments on a small refrigeration and heat pump system were performed, and the working conditions were decided at different water temperatures and flow rates in condenser or evaporator,which were compared with those experimental data of R22 in the same working conditions.The non-azeotropic mixtures working fluid R290/R600a/R123(50%/10%/40%,mass) may become an alternative of R22 for heat pump application.