Room temperature photoluminescence (PL) properties of the Tb3+ ion implanted nonstoichiometric silicon nitride (Tb3+:SiNx) and silicon dioxide (Tb3+:SiOx) were studied. The films were deposited by plasma-enhanced chemical vapor deposition and then annealed at different temperatures for 1 h in flowing N2 before or after the implantation. Results show that there are four intense PL peaks due to the intra-4f transitions of Tb3+ in the wavelength from 470 to 625 nm for both kinds of films. Moreover, after postannealing at 1000 °C, the integrated PL intensity of Tb3+:SiNx is much higher than that of Tb3+:SiOx. The energy transfer from the defect related energy levels to the Tb3+ ions will enhance the 5D4→7Fk (k=3–6) luminescence of Tb3+ ions.