The investigation of the microstructure and mechanical properties has been conducted on AA3003 alloy produced by a novel intense plastic straining process named accumulativev roll-bonding (ARB). The results show that ultra-fine grained 3003 alloy having mean grain size of 700-800 nm was successfully produced by the 250degreesC-ARB. The average grain sizes of 250degreesC-ARB samples were reduced greatly from about 10.2 mum initially to 700-800 nm. After 6 cycles of ARB, the whole volume of the material was filled with ultra-fine grains with high angle boundaries. The tensile strength of the ARB processed 3003 alloy (after 6 cycles) is considerably higher than that of the initial material, and about 1.5 times higher than that of commercially available fully-hardened (H18) 3003 alloy. Strengthening in ARB processed 3003 alloy may be attributed to strain hardening and grain refinement hardening.