Silicon oxynitride films were deposited in very-high-frequency (40.68 MHz) plasma enhanced chemical vapor deposition (VHF-PECVD), and subsequently annealed between 400 and 1200°C in N2 ambient. The effect of annealing temperature on the PL characteristics of the samples was investigated. The experimental results reveal that a broad PL peak around 430 nm (2.88eV) appears in all of the samples. The maximum intensity of this broad PL peak was obtained in the sample annealed at 400°C. The PL characteristics of the annealed samples were discussed.