Abstarct: Abstract In this research, graphene oxide/zinc sulfide (GO/ZnS) nanocomposite was prepared in a simple and easy way by reacting a mixture of zinc acetate and graphene oxide in the vicinity of sodium didecyl sulfate (SDS) with thioacetamide. This nanocomposite was identified using common methods such as Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction Pattern (XRD), Raman Spectroscopy, Scanning Electron Microscope (FE-SEM) and Energy Diffraction Spectroscopy X-ray (EDS). GO/ZnS composite was used in the process of photocatalytic degradation of rhodamine B. The degradation process of Rhodamine B and the influencing factors such as pH of the solution, initial concentration of the dye and amount of photocatalyst were investigated. Rhodamine B solution with a concentration of 5 ppm under optimal conditions of pH equal to 7.20, amount of 0.010 g of GO/ZnS nanocomposite and under the radiation of 50 W mercury lamp for 75 minutes, was degraded by 93.18%. The results showed that the degradation process of Rhodamine B by GO/ZnS composite was consistent with the first-order kinetic model and its rate constant was 0.0298 min-1.