Properties of the chemical waves emerging from the mask edge were investigated for the Ru(bpy)(3)(2+)-catalyzed Belousov-Zhabotinsky reaction under steady illumination while varying the initial concentration of malonic acid ([MA](0)) systematically. The wave velocity, the wavelength and the thickness of the oxidized band were found to decrease monotonously with [MA](0). The obtained results were qualitatively interpreted based on the temporal oscillations measured in a batch reactor. A key effect caused by increasing [MA](0) was identified to be the enhancement of the reduction rate of Ru(bpy)(3)(3+).