The effect of light on the Bray-Liebhafsky oscillatory reaction was studied at 55 degreesC. It was found that both the induction time and period decreased with the increasing light intensity, and at a critical value of intensity, dependent on the initial concentration of the reactants, oscillation disappeared. The reaction scheme proposed by Schmitz was extended with a direct reaction of I-2 with H2O2. By taking into account the latter reaction, the oscillations were numerically calculated and good agreements with the experimental data were found.