Provided are a flue gas denitration catalyst having high denitration activity and capable of suppressing a side reaction, that is, oxidation of SO.sub.2; and a preparation process of the catalyst. The flue gas denitration catalyst comprises TiO.sub.2, WO.sub.3 and V.sub.2O.sub.5. In the surface layer of the catalyst within 200 .mu.m from the surface thereof, V.sub.2O.sub.5 is supported on a carrier containing TiO.sub.2 and WO.sub.3. The supported amounts of V.sub.2O.sub.5 range from 0.4 to 5 wt. % based on the weight of the surface layer and range from 0.1 to 0.9 wt. % based on the total weight of the catalyst. The V.sub.2O.sub.5 thus supported has a crystallite size of less than 10 nm as measured by X-ray diffraction. The catalyst can be available by preparing a mixture containing TiO.sub.2 and WO.sub.3 and having V.sub.2O.sub.5 supported on the surface of an extruded product of the prepared mixture by a vapor phase method. The catalyst can be also available by having V.sub.2O.sub.5 supported on a powder of the prepared mixture by a vapor phase method and having the resulting powder supported on the surface of a formed product.