In the present work, the Co/TiO 2 nanocomposite was prepared by sol-gel method. The structural and optical properties of nanocomposite were studied using, X-ray diffraction (XRD) and diffuse reflectance UV-VIS spectrometry. The XRD spectra revealed its tetrahedral anatase structure. The grain size and optical properties of composite are also reported. Syntesied Co/TiO 2 photocatalyst showed excellent activity for the photodegradation of Methyl orange whether under visible and ultraviolet light irradiation.