In this work, CeO2 nanocubes hybridized g-C3N4 composites had been facilely synthesized to investigate the interfacial effects on photocatalytic water splitting. The c-CeO2/g-C3N4 composites exhibited the superior photocatalytic hydrogen evolution under visible light irradiation. The optimal c-CeO2 loading content was 5wt%, with the H2 evolution of 4300μmolg−1 for 5h illumination, higher than that of pristine CeO2, g-C3N4 and irregular CeO2 nanoparticles/g-C3N4. Moreover, UV–vis DRS, PL spectra and photoelectrochemical measurements demonstrated that 5wt% c-CeO2/g-C3N4 composite possessed more visible light adsorption and faster charge transfer, which was attributed to the stronger interfacial effects through the presence of the hydrogen bond and p-π hybrid between c-CeO2 {100} and g-C3N4, revealed by the FT-IR and XPS results. The work suggested that engineering the structures of the CeO2 and g-C3N4 interface could be an effective strategy to obtain excellent photocatalysts.