Based　on　density　functional　theory　and　generalized　gradient　approximation　calculations,　the　adsorption　of　Co2B2　and　Ni2B2　clusters　on　the　rutile　TiO2　(110)　surface　has　been　investigated　utilizing　periodic　supercell　models.　Unambiguously,　the　results　demonstrate　that　the　hollow　site　turns　out　to　be　preferable　for　Co(2)B2　cluster　while　Ti-2　site　is　for　Ni2B2　cluster　to　adsorb.　Orbital　population　analysis　indicates　a　strong　interaction　between　Co2B2　and　O　atom　of　TiO2　surface,　which　can　be　attributed　to　the　overlap　of　Co　3d　and　surface　O　2p　orbital.　Similarly,　for　Ni2B2,　the　bonding　interaction　occurs　mostly　through　the　interaction　of　Ni　3d/4s　and　O　2p　orbitals.　Note　that,　there　is　also　an　interaction　within　the　Co2B2　clusters　(Ni2B2)　through　B　2s/2p　and　Co　3d　orbitals　(Ni　3d/4s).　Moreover,　orbital　analysis　results　shows　that　the　strong　bonding　between　Ni2B2　and　Ti-2　site　is　due　to　the　overlap　of　HOMO　of　Ni2B2　and　d-orbital　of　five-coordinated　titanium　atoms.