In this paper, the changes of photoluminescence (PL) spectra according to varied measuring temperatures, annealing temperatures, and excition wavelength in a-C:H films deposited by rf glow discharge are studied. The experimental results show that the PL efficiency becomes lower with increasing the measuring temperature or annealing temperature. We give an explanation to the phenomena using the two-phase model in a-C:H system. Furthermore, the PL spectra also changes with excitation energy; and as the latter geis near the optical gap Eopt, the emission intensity reaches its maximum.