The effect of sacrificial reagents (SRs) on photocatalytic H-2 evolution rate over different photocatalysts was systematically studied. Zn0.5Cd0.5S, graphitic carbon nitride (g-C3N4), and TiO2 were chosen as typical photocatalysts, while alcohols, amines, carboxylic acids, and inorganic Na2S/Na2SO3 were chosen as SRs. The results indicate that Na2S/Na2SO3, methanol, and triethanolamine are the most suitable SRs for Zn0.5Cd0.5S, TiO2, and g-C3N4, respectively. It was found that in selecting organic SRs, both the permittivity and oxidation potential have profound effects on the H-2 production efficiency, which will provide basis for choosing appropriate SRs for different photocatalysts.