Herein, MoS 2 /TiO 2 nanobelts heterojunction have been successfully synthesized by in situ growth method for photocatalytic reduction of Cr(VI). TiO 2 nanobelts (NBs) with rough surface were prepared firstly by acidic treatment process, which is beneficial for deposition and growth of MoS 2 to form heterojunctions. As a result of special energy level offset and nanostructure, MoS 2 /TiO 2 NBs composite were endowed with higher light-harvesting capacity and charge transportation efficiency, which are indispensible merits for excellent photocatalytic activity. The photocatalytic reduction of Cr(VI) reveals that the synthesized MoS 2 /TiO 2 NBs composite have superior photocatalytic ability than other samples. Meanwhile, a photoreduction mechanism is proposed based on the systematic investigation, where the photogenerated electrons are demonstrated as the dominant reductive species to reduce Cr(VI) to Cr(III).