Removing residues of antibiotics and Cephalexin in water environment is a very difficult. Co-TiO2/SiO2material has been tested to assess its ability to treat cephalexin. SiO2 has absorption properties andlarge contact surface area suitable for impregnating TiO2. Cobalt with 0.9% concentration is doped inTiO2/SiO2 material, which increases the photocatalytic ability of the material in visible light. Co-TiO2/SiO2 samples provide Cephalexin degradation faster than un-doped samples. Cephalexin from aninitial concentration of 10 ppm was completely decomposed after 30 and 60 minutes of illumination(10W, 365 nm) for 9Co-TiO2/SiO2 and 1Co -TiO2/SiO2 materials, respectively. Co-TiO2/SiO2 is one ofthe promising materials for cephalexin removal in water with visible light.Keywords: photocatalyst, TiO2, SiO2, Coban, Cephalexin, water environment