W,N co-doped TiO_2 nanoparticles were synthesized by a sol-gel method.The prepared samples were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS) and diffuse reflectance spectrophotometry(DRS).The results showed that the codoped photocatalysts were essentially uniform spherical particles with the smallest particle size of22.5 nm.Compared to un-doped TiO_2,N-TiO_2 and P-25,the absorption edge of the W,N co-doped TiO_2shifted to longer wavelength and its photocatalytic activity for degradation of methyl orange(MO) under Xe-lamp(350 W) was higher. W, N co-doped TiO 2 nanoparticles were synthesized by a sol-gel method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectrophotometry (DRS). The results showed that the codoped photocatalysts were essentially uniform spherical particles with the smallest particle size of 22.5 nm. Compared to un -doped TiO 2, N-TiO 2 and P-25, the absorption edge of the W, N co-doped TiO 2 shifted to longer wavelength and its photocatalytic activity for degradation of methyl orange (MO) under Xe-lamp (350 W) was higher.