A highly active photocatalyst TiO2/g-C3N4 was facilely synthesized by a facile two-step method, sol-gel method and calcination using Ti(OBu)4 as Ti source and melamine as nitrogen source. The structural and morphological properties of the resultant photocatalysts were characterized. The results showed that TiO2/g-C3N4 was formed and TiO2 was beset with graphite-like carbon nitride of layer structure. TiO2/g-C3N4 exhibited obviously enhanced visible light photocatalytic activity, and the degradation efficiency of Methylene blue (MB) reached 94.46% after irradiation for 1h, which was much higher than that of g-C3N4 and TiO2. The improved photocatalytic activity of TiO2/g-C3N4 was attributable to its wide spectrum responsive range, strong visible light adsorption capability, and the synergistic effect between TiO2 and g-C3N4. The mechanism of photocatalytic reaction was discussed.