Using　the　first-principles　method,　the　configurations　and　electronic　structures　for　the　adsorption　of　CO　molecule　on　TiC(001)　surface　were　investigated　in　details　with　a　slab　model.　Our　results　showed　that　the　CO　molecule　tended　to　occupy　the　atop　site　of　the　surface　Ti　atom　through　its　C　ending,　and　the　predicted　adsorption　energy,　the　positions　of　CO　valence　levels　and　the　red　shift　of　C-O　stretching　frequency　were　in　agreement　with　the　experimental　observations.　By　analyzing　the　band　structures　and　Mulliken　population.　when　CO　molecule　was　adsorbed　by　C　ending,　the　compositions　and　energy　levels　of　the　corresponding　5　sigma　and　2　pi*　states　changed　obviously　with　respect　to　CO　in　gas-phase,　especially　for　the　case　that　CO　sited　at　the　bridge　site　between　two　neighbor　Ti　atoms.　Furthermore,　the　role　of　the　surface　state　during　the　CO　adsorption　was　discussed.