The　adsorption　of　benzene　on　CuCl(111)　surface　has　been　studied　by　density　functional　theory　calculation　with　the　GGA　Perdew-Wang　method.　The　calculated　results　indicate　that　benzene　adsorption　On　surface　Cl　site　is　the　most　favorable.　The　smaller　the　coverage　is,　the　more　stable　the　adsorption　is.　The　predicted　adsorption　energy　for　benzene　adsorption　on　Cl　site　is　74　kJ/mol,　in　fair　agreement　with　the　experimental　results.　The　benzene　adsorption　oil　top　and　hollow　sites　is　physical　adsorption.　The　density　of　states　and　the　charge　population　before　and　after　the　adsorption　have　also　been　analyzed.　The　calculated　results　show　the　back　donation　of　Cu　3d　electrons　to　the　pi*　anti-bonding　orbital　of　benzene,　which　weakens　the　aromatic　bond.