The　electronic　structures　of　CaNiN　as　well　as　its　metallic　conductivity　and　magnetism　have　been　studied　by　using　DFT　method.　The　calculated　results　indicate　that,　due　to　the　weak　interaction　between　the　NiN2-　chains,　the　band　structures　of　NiN　with　different　dimensions　are　similar,　which　also　determine　the　conductivity　and　magnetism　of　the　compound.　Compared　with　[MX]　chains　(RI　=　Pt,　Pd;　X　=　halogen　atom),　it　shows　that　the　undistortion　of　the　NiN2-　chain　is　mainly　originated　from　the　competition　between　the　decrease　of　the　orbital　energy　and　the　increase　of　the　paired　energy.　For　the　[MX]　chains,　the　latter　effect　is　dominant　and　hence,　the　distortion　of　their　chains　is　observed.　It　seems　that　the　smaller　distortion　the　compound　has,　the　more　favorable　its　magnetism　will　be.