Abstract: Experiments were conducted to investigate the effect of grain refining mechanism on the microstructure and mechanical properties of 1060 commercially pure aluminum in accumulative roll bonding (ARB), in which two kinds of routes, Route A and Route B, were employed. The results show that the effectiveness of Route A is better than Route B. After ARB of 7 passes, the microstructure of the specimen by Route A consists of thin elongated fibriform grains with an average size of 470 nm, but that by Route B does compressed grains with an average size of 680 nm. The improvement in tensile strength by Route A is greater than that by Route B. The strengthening mechanism of 1060 commercially pure aluminum by ARB is fine-grain strengthening. The deformation rule and the formation mechanism of fine grains were analyzed elementarily in ARB process.