Tungsten tailing powders were activated by mechanical and chemical methods for use as cementitious material in mortar. The composition, microstructure and properties of tungsten tailing were characterized with X-ray fluorescence, X-ray diffraction, scanning electron microscopy, Fourier transformation infrared spectroscopy, differential scanning calorimetry and thermogravimetry. The results showed that garnet was the major mineral in the tailing, which possessed excellent chemical and structural stability but poor cementitious property. Mechanical milling and chemical activator were used to activate the tailing. The activation effects and structural evolution of activated tungsten tailing were assessed, and the possible mechanism was discussed. A series of cement mortar samples was prepared to evaluate the cementitious property of the activated tailing. Effects of activation condition and mixture proportion on mechanical strength of cement mortar were investigated. The mechanical and chemical activations could synergistically improve the cementitious property. The properties of cement mixed with 20% of the activated tailing were well comparable with those of 42.5 ordinary Portland cement. The activated tailing as cementitious material could be used to solve the tailings pollution and reduce cost in cement industry. (C) 2015 Elsevier B.V. All rights reserved.