In　order　to　improve　the　speed　and　efficiency　of　reduction　algorithm　of　core　influence　attributes,　a　new　core　computation　algorithm　based　on　positive　region　is　provided.　The　positive　region　based　on　radix　sorting　is　used　to　get　the　positive　region　condition　attributes　set　of　decision　attributes　and　the　condition　attribute　set　which　excludes　one　of　the　condition　attributes　of　decision　attribute　positive　region.　Then　the　difference　between　the　two　radices　of　positive　regions　is　calculated　to　judge　whether　the　condition　attribute　is　a　core　attribute,　thereby　all　the　condition　attributes　are　judged　and　the　required　core　is　quickly　acquired.　The　time　complexity　of　the　proposed　algorithm　is　O(|C||U|).　Experimental　results　show　that　the　core　computation　time　increases　linearly　with　the　increasing　number　of　entries,　and　the　computation　time　is　only　0.6%　of　the　contrastive　algorithm　when　the　entries　is　maximum.　Meanwhile,　it　is　shown　that　the　algorithm　is　well　suitable　for　various　kinds　of　data　sets.