Natural sphalerite as a novel cost-effective photocatalyst was characterized by means of electron microprobe analy-is (EMPA), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL),transmission electron microscope (TEM), scanning electron microscope (SEM) and Hall-effect measurements. The results show that the visible light response of the natural sphalerite sample results from the presence of substituting metal ions. Besides, the variable-valence element of Fe can act as a hole scavenger in the process of Fe2+ +h+→ Fe3+, thus improving the efficiency of conduction band electrons and strengthening the photoactivity. Cleavage planes and fracture surfaces can improve the photocatalytic activity by providing more active sites than perfect faces. Other defects like charge vacancies and lattice expansion with their possible roles of improving the efficiency of electron_hole pair separation are analyzed. The photoreductive reactions prove that the natural sphalerite sample exhibits a high photoactivity on reducing methyl orange under visible light irradiation, which is consistent with its specific characterization. The results also demonstrate that natural sphalerite as a new cost-effective photocatalyst driven by visible light will have certain application prospects in environmental remediation. 