The rGO/ZnSnO3 composites have been elaborately synthesized by a facile solution-based self-assembly synthesis method at low temperature. The structure, morphology, thermal stability, composition and specific surface area of composite were characterized by XRD, SEM, TG, XPS and BET analysis, respectively. The sensing experiments show that the sensor based on 3 wt% rGO composite not only exhibits high sensitivity (low limit of detection), excellent selectivity and linearity relationship between responses and formaldehyde concentration from 1 to 10 ppm, but also exhibits fast response and recovery at operating temperature of 103 degrees C. The enhanced sensing mechanism of the hybrid to formaldehyde was discussed in detail, which can mainly be ascribed to the large specific surface area for gas adsorption, porous channels for gas diffusion, the fast carrier transport benefited from rGO and the formation of heterojunction at the interface between the rGO and ZnSnO3. (C) 2017 Elsevier B.V. All rights reserved.