Cu2ZnSnS4 (CZTS) as a narrow band gap semiconductor had been used to couple with TiO2 for enhancing the utilization of solar energy. In this article, the TiO2-thiol reduce grapheme oxide (TrGO)-CZTS heterostructure is constructed via a facile in-situ solvothermal method. The in-situ solvothermal method could acquire the uniform particles sizes and no aggregation of CZTS by adjusting the sulfur source and reactant solvent. The formation mechanism of TiO2-TrGO-CZTS structure and the combination behavior of TrGO and CZTS were proposed. The thiol groups in TrGO give the site for CZTS to grow and form the chemical bond which could stabilize the connection of CZTS and TrGO. The in-situ reaction CZTS composite electrode exhibited a better photoelectrochemical performance than the self-assemble CZTS. (C) 2016 Elsevier B.V. All rights reserved.