The effect of N incorporation on the structure and magnetic properties of CoPt thin filmsdeposited on glass substrates with TiN seed layers has been investigated. During the deposition of CoPt, introducing 20% N2 into Ar atmosphere promotes the (001) texture and enhances the perpendicular coercivity of CoPt film compared with the filmdeposited in pure Ar and post-annealed under the same conditions. From the in situx-ray diffraction results, it is confirmed that N incorporation expands the lattice parameter of CoPt, which favors the epitaxialgrowth of CoPt on TiN. During the post-annealing process, N releases from CoPt film and promotes the L10 ordering transformation of CoPt.