Energy conservation and environmental pollution elimination are among the most important factors that contribute to improving refrigeration and air conditioning systems. This article focused on the effect of nanoparticles Al2O3 mixed with PAG oil in concertation 0.14 % used base fluid R600a (isobutane) on a one ton vapor compression refrigeration system’s performance and compare it with the mixed refrigerant (R290/R600a) in ratio 60 % /40 %, in vapour compression system with double tube heat exchanger experimentally three ratios were tested(0.1,0.12,0.14) % and it was noted that 0.14 % was the ratio that had the most impact on the results. Adding Al2O3 in concertation 0.14% with R600a the reading recorded in time about 80(min) operation, the study noted increased in COP approximately in (R600a/Al2O3) is 35 % compared with COP in mixed refrigerant (60/40) % R290/R600a is 28%, and noted reduced in work of compressor is 102 KJ/Kg compare with mixed refrigerant (R290/R600a) ratio 60% /40% that 110 KJ/Kg improvement about 9%. The evaporator inlet temperature reach to -20oC in (R600a/Al2O3) and -15oC in mixed refrigerant (R290/R600a)60%/ 40%, so the refrigerating effect of (R600a/Al2O3) nano refrigerant at a concentration of 0.14 % is 438 KJ/Kg showed an improvement of approximately 29%. due to decreased in temperature inlet to evaporator. Theoretical results were determined using simulation software ProII and EES software based on mathematical models of vapour compression system components, the COP shows 15% difference due to measurement errors.