The LiNbO3 planar optical waveguides are fabricated by 3.0-MeV C+ ion implantation at the doses of 1.5–10.5×10(14) cm-2. Both TE and TM modes are observed by prism coupling method (m lines). The reconstructed refractive index profiles of the guiding region show that extraordinary index has an enhancement compared with the substrate of LiNbO3, while ordinary index experiences a typical “barrier” change. The modal analysis of the waveguides shows a good confinement of light in fundamental TM mode. The tendency of effective refractive index (decrease after the annealing for TE and increase after annealing for TM) suggests a moderate recovery of the lattice.