A series of mesoporous TiO2spheres of nanosized crystals with high monodispersity and dimensionalhomogeneity are synthesized by a simple reflux method. In order to improve the visible light responseand to further narrow the band bap of TiO2sphere, nitrogen is used as the dopant in a hydrothermalmethod. Different from the traditional nitrogen doping in TiO2solid sphere, the nitrogen is uniformlydistributed from bulk to the surface of mesoporous TiO2sphere, which is beneficial to the generationof the successive energy bands inside the TiO2band gap. Interestingly, the XPS results indicate that thenitrogen doping concentration could reach 1.31% (only 0.17% for nitrogen doped solid TiO2sphere), owingto the homogeneous doping in the mesoporous TiO2spheres. The nitrogen doped TiO2spheres exhibitsuch excellent characteristics as high specific area, relatively small particle size, pure anatase phase andexcellent UV–vis absorption capacity in the range of 400–800 nm, which are all beneficial to the photo-degradation of Rhodamine B under the visible light irradiation. The high photocatalytic activity could beascribed to the homogeneous nitrogen doping on the deep adjustment of energy band of TiO2spherefrom the bulk to the surface.