New wolframite-type oxides (Co1-xNixWO4) with various compositions have been prepared by a combustion method and carburized using a temperature-programmed reaction. Catalytic performance was evaluated in a continuous flow reactor using pyridine hydrodenitrogenation (HDN) as the model reaction. The carbide phase composition is markedly affected by the atomic ratio (i.e., Ni/Ni + Co). The mixed Co, Ni and W carbides are active catalysts for pyridine HDN reaction; however, they undergo deactivation due to graphitic carbon deposition and segregation.