The systematic investigation of In ions doped ZnGa2O4 applying to photocatalytic H-2 evolution (PHE) under simulated solar-light irradiation was first reported here. A series of Zn(InxGa1-x)(2)O-4 (x = 0 to 0.4) solid-solutions were obtained by sol-gel method and characterized by XRD, SEM, elemental mapping, XPS, UV-Vis DRS and N-2 adsorption measures. The concentration of In3+ ions remarkably enhanced the light-harvesting capability of Zn(InxGa1-x)(2)O-4 solid-solutions in the visible-light region, and successfully regulated the positions of the CB-bottom potential, ultimately improving the photocatalytic capabilities under simulated solar-light irradiation. Among composites containing different In3+ ions dosages, Zn(In0.1Ga0.9)(2)O-4 demonstrated the most excellent photocatalytic capability for solar-light-driven PHE reaction (H-2: 240.6 mu mol/h/g), in which the stability of the Zn(In0.1Ga0.9)(2)O-4 was confirmed by several techniques. (C) 2019 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.