A series of WO3/Nb2O5 was prepared by impregnation method. The structure, components, morphology, acidic property, specific surface area and porosity of the catalysts were fully characterized by XRD, EDS, TEM, NH3-TPD, Py-IR, BET, BJH. And its catalytic properties in conversion of fructose to 5-hydroxymethylfurfural (HMF) are studied. The factors such as tungsten oxide loading amount, reaction time, temperature and amount of catalyst are investigated. It is found the tungsten oxide loading amount plays important role on the structure, acidic property and catalytic properties of the catalysts. With the increase of tungsten loading amount, the molecular structure of tungsten oxide changes from the surface dispersed amorphous WO3 to the crystalline WO3, and the presence of appropriate amount of WO3 clusters on Nb2O5 leads to generation of maximum number strong acidic sites and additional number of Brønsted acid sites in the catalyst, thereby increasing the conversion of fructose. However, the crystalline WO3 is not conducive to the production of HMF. The selectivity and yield of HMF can respectively reach 85.4% and 49.6% within 1 h at 170 ℃ over 100 mg 5%-WO3/Nb2O5 catalyst．