A series of boron-doped TiO2/SO42- photocatalysts were successfully prepared by the solid-state thermolysis method. Several technologies including X-ray powder diffraction ( XRD), Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectra (UV-vis DRS) and X-ray photoelectron spectroscopy ( XPS) were employed to investigate the phase structures，diffuse reflectance spectroscope (DRS) and surface chemical states. The photocatalytic properties of B-doped TiO2 were evaluated by degrading methylene blue (MB) under UV irradiation and visible-light irradiation. Results showed that B species have been doped into the crystal lattice of TiO2 with B doped in the form of substitutional and interstitial B, and can affect the surface chemical forms and structures of surface hydroxyl groups and SO42- groups. The experimental results of UV-vis DRS further indicate that the as-prepared photocatalysts with different B contents exhibited the stronger absorption in the visible light region and UV region. Compared to P25, B-doped TiO2 samples showed better activities for degradation of methylene blue (MB) under UV irradiation and visible light irradiation, and exhibited the highest photocatalytic activity when the molar doping ratio of B was 0.25. The superior performance of this sample is ascribed to the synergy and interplay among the decrease of the optical energy gap, efficient charge separation and surface hydroxyl groups.