The local structure of tungsten species in tungsten-zirconium-oxide catalysts(WO(x)-ZrO(2)) was first investigated by W K-edge x-ray absorption spectroscopic techniques. A proportion of WO(4) to the total WO, species was quantitatively analyzed with W L(1)-edge x-ray absorption near edge structure (XANES). Tungsten species in 15 wt% WO(x)-ZrO(2), which is the most active for n-butane skeletal isomerization, consists of a mixture of WO(3)-ZrO(2) solid solution, WO(6) aggregate and WO(4) species on the catalyst surface. The tungsten species does not possess long-range ordering. Copyright (C) 2008 John Wiley & Sons, Ltd.