The effects of tungsten doping on the morphology, stability and photocatalytic activity of TiO2 nanocrystal colloids were investigated. The nanostructure, chemical state of Ti, W, O, and the properties of tungsten doped TiO2 samples were investigated carefully by TEM, XRD, XPS, UV-vis, PL and photocatalytic degradation experiments. And the structure-activity relationship was discussed according to the analysis and measurement results. The analysis results reveal that the morphology, zeta potential and photocatalytic activity of TiO2 nanocrystals can be easily tuned by changing the tungsten doping concentration. The tungsten doped TiO2 colloid combines the characters of high dispersity and high photocatalytic activity. (C) 2013 Elsevier Ltd. All rights reserved.