In this paper, AgCl/BiOCl composite nanostructure has been synthesized by a facile ion exchange route between black BiOCl microsphere and AgNO 3 solution. The as-obtain products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). Photodegradation experiments show that the photocatalytic activity of AgCl/BiOCl composite nanostructure is improved greatly by composited AgCl nanoparticles, compared with pure black BiOCl microsphere. The excellent photocatalytic activity of AgCl/BiOCl composite nanostructure with special surface morphology may be attributed to decreasing recombination of the photo-excited electron–hole pairs. In addition, AgCl/BiOCl composite possesses strong absorption to visible light which can also improve the photocatalytic efficiency.