The difference in annealing characteristics of oxygen free copper (OFC) and deoxidized low-phosphorous copper (DLP) processed by ARB was studied. The copper alloys processed by eight cycles of the ARB were annealed for 10 minutes at various temperatures ranging from 100 to 400°C. The variation of microstructure and mechanical properties with annealing was significantly different in both copper alloys. In case of OFC, the ultrafine grained (UFG) structure formed by the ARB still remained up to 200°C, and above 200°C it was completely replaced with a coarse grained structure due to an occurrence of the conventional recrystallization. However, in case of DLP, the recrystallization did not occur even at 350°C. The strength of the OFC also decreased significantly at annealing temperatures above 200°C, while the hardness of the DLP did not decrease so largely up to 350°C. These differences in annealing characteristics in both copper alloys were discussed in terms of purity.