The　structural　and　electronic　properties　of　cation　doping　on　the　spinel　LiMn2O4　were　investigated　by　the　first-principles　theory.　The　calculated　results　indicate　that　due　to　the　formation　energy　of　LiAl0.5Mn1.5O4　is　the　smallest,　the　structure　of　LiAl0.5Mn1.5O4　may　be　the　most　stable　material,　so　the　cycle　performance　may　be　the　best.　Both　Cr-O　and　Sr-O　bonds　are　longer　than　Co-O　and　Al-O　bonds,　thereby　the　cycle　performance　of　LiAl0.5Mn1.5O4　and　LiCo0.5Mn1.5O4　may　be　better.　For　LiCr0.5Mn1.5O4　and　LiSr0.5Mn1.5O4,　the　charge　density　among　Sr,　Cr,　Mn　and　O　atoms　decreases,　so　the　partial　charge　from　Sr,　Cr,　Mn　and　O　atoms　is　centralized　near　Li-site　atoms,　which　is　beneficial　to　the　transition　of　lithium.　Therefore　the　electronic　conductivity　of　LiCr0.5Mn1.5O4　and　LiSr0.5Mn1.5O4　is　improved.　For　LiAl0.5Mn1.5O4　and　LiCo0.5Mn1.5O4,　the　charge　overlap　around　Mn,　Ni　and　O　atoms　significantly　increased,　the　charge　of　Co,　Al,　Mn　and　O　atoms　formed　Co-O,　Al-O　and　Mn-O　stable　bonds,　therefore　LiAl0.5Mn1.5O4　and　LiCo0.5Mn1.5O4　structural　stability　is　dramatically　increased　and　may　behave　better　electronic　properties　and　more　capacity.