The effect of sacrificial reagents (SRs) on photocatalytic H2 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 H2 production efficiency, which will provide basis for choosing appropriate SRs for different photocatalysts.