A novel copper and phosphorus codoped TiO2 photocatalyst was synthesized by modified sol–gel method using tetrabutyl titanate, Cu(NO3)2 and H3PO4 as precursors. The samples were characterized by XRD, TEM, TGA, EDX. The TGA indicated the calcination temperature is 450°C. The XRD results showed undoped and Cu, P-codoped TiO2 nanoparticles only include anatase phase, and the temperture of crystalline phase transform for Cu, P codeped TiO2 had changed compared with undoped. The TEM analysis revealed the doping of Cu and P suppressed the growth of TiO2 grains. The photocatalytic activity of samples was tested for degradation of 20 mg·L−1 methyl orange (MO) solutions. The results showed photocatalytic activity of the catalysts with 0.5% Cu, 0.375% P-codoped TiO2 was higher than pure TiO2 under ultraviolet (UV).