A simple model of single-bubble sonoluminescence (SBSL) is proposed. The model is based on the approximation of pressure uniformity, while the mass and the temperature in the bubble remain nonuniform. The water vapor evaporation and condensation at the bubble wall and the water vapor diffusion versus the noble gas inside the bubble are also considered. The number density of electrons is estimated by the Saha equation, and in evaluating the light emission from bubbles, bremsstrahlung from electron-neutral particle and electron-ion collisions, as well as recombination radiation, are accounted for. The intensity of light emission at different water temperature is calculated. It has been found that the results obtained using the bremsstrahlung model at a water temperature of 0 ℃ agree with the experimental data. When the wtater tempreture increases, for example at 20 ℃ or above 20 ℃, the calculated results differ from the experimental data in magnitude. If chemical reactions are taken into account, the results by using bremsstrahlung model are always lower than the experimental data by 2 order of magnitude.