5A02　Al　alloys　with　gradient　structures　were　designed　by　controlling　the　number　of　torsional　revolutions　of　1,　2,　4,　and　8.　The　results　showed　that　the　yield　strength　increased　and　the　uniform　elongation　decreased　with　the　increasing　torsional　revolution.　Preferable　comprehensive　properties　with　yield　strength　of　196.7　&　PLUSMN;　3.7　MPa　and　uniform　elongation　of　1.9　&　PLUSMN;　0.2　%　were　obtained　at　the　torsional　revolution　of　4.　It　is　revealed　that　the　increment　in　yield　strength　contributed　by　HDI　stress,　grain　refinement　and　the　introduction　of　dislocations,　in　which　dislocation　strengthening　played　the　major　role.　The　ductility　came　from　HDI　hardening　and　the　strain　hardening　ability　of　the　center　region　with　low　dislocation　density.　The　finding　provided　a　promising　and　cost-effective　method　to　enhance　mechanical　properties　of　Al　alloys　by　tailoring　gradient　structures.