Mo-N-co-doped mesoporous TiO2 microspheres were synthesized via a solvothermal method, followed by nitriding treatment under ammonia gas flow. The efficiency of the samples was investigated by monitoring the degradation of Rhodamine-B under visible light irradiation. The experimental results revealed that Mo-N-co-doped mesoporous TiO2 microspheres showed better performances than Mo-TiO2 microspheres. It was observed that; 0.1% molar quantity of Mo doped on TiO2 at 500°C for 2h under nitriding conditions gave highest photocatalytic activities. The nitridation under ammonia gas of Mo-TiO2 samples created oxygen vacant sites and led to incorporation of substitutional and interstitial Nitrogen. The enhanced visible light photocatalytic activities of Mo-N-co-doped TiO2 photocatalyst was attributed to the large surface areas, narrow band gap and intense light absorbance in visible region. This study may create a promising and eco-friendly method towards synthesis of metal and non-metals co-doped on semiconductor materials to improve their photocatalytic activities and applications.