Tb-doped silicon carbide (SiC:Tb) films were deposited on porous silicon (PS) substrates by rf co-sputtering. The prepared films were annealed in N-2 atmosphere at different temperature from 500-1000 degrees C. The effects of annealing on the structure and photo luminescence (PL) characters of the films were investigated by Atomic force microscopy (AFM), Raman, Fourier transform infrared spectroscope (FTIR) and fluorescence spectrometer. The SiOx layer at the SiC:Tb/PS interface was destroyed as the annealing temperature increasing, and the oxygen-deficiency centers (ODCs) increased. The SiOx layer was restructured at higher annealing temperature and the ODCs decreased. This is the reason of origin and changing of UV band in PL spectra. The visible band origins from Tb3+, and is stable with annealing temperature.