The interaction between implanted nitrogen atom and transition metal iron at the anatase TiO2(101) surface is investigated by the periodic density functional theory calculations. Substitutional and interstitial configurations and formation energies for Fe-doping, and several N and Fe atom codopings at different sites of the (101) surface are considered. Our formation energy calculations suggest that when Fe atom transfers from surface to body, it is subjected to a larger energy barrier while asynergetic effect takes place between the nitrogen and the codoped Fe in the surface. The analyses of the electronic structure and densities of states show that the property of half-metallic appears, with N and Fe codoped.