The　electronic　structure　and　optical　properties　of　TiNx　system　in　different　N　content　(x=0,　0.5,　0.6　and　1)　corresponding　to　the　TiNx　super　cell　structure　were　calculated　by　the　first　principle　method.　The　calculation　results　showed　that:　TiNx　were　typically　metal　properties,　but　this　properties　of　TiNx　were　weakened　according　to　the　increase　of　the　content　of　N.　The　dielectric　function　and　reflectivity　function　of　TiNx　(x=0,　0.5,　0.6　and　1)　crystal　were　accurately　calculated.　The　calculation　results　coincided　with　the　existing　theory　well,　which　offered　theoretical　data　for　TiNx　materials　in　molecular　atomic　scale　design　and　application　in　further.