A Mn doped TiO2 was synthesized by hydrothermal treatment of titanium boride and manganese chloride. The doped nano powders were fabricated by adding ammonium water into mother solution which was obtained by hydrothermal. The calcination of precursory powders were at the temperature of 400-600 °C which resulted in the formation of anatase with small amount of rutile phase. The shift of valence band maximum (VBM) toward the lower binding energies was observed by measuring the position of VBM with reference to the Fermi level, which contributed to the significant red-shift of absorption edges. X-ray photoelectron spectroscopy (XPS) measurement show that the manganese exist both 4+ and 3+ valance, which may have a temperate replacing of Ti4+ because of the charge compensation compared with 2+ and 3+ valance. The property of photoelectric conversion was detected by evaluating the photocurrent under visible light (>420 nm), and the fluorescence spectra also proved that 6%-Mn doped TiO2 (DM6) show a better photoelectric conversion performance.