CoO_x-based catalysts have been suggested as promising catalysts for C–H bond activation and C–C bond formation. For supported CoO_x catalysts, surface concentration, reducibility, and oxidation state of Co species are important properties determining the catalytic performance. Herein, we prepare alumina-supported Co-V oxide catalysts to enhance the catalytic performance for propane dehydrogenation (PDH). The change in the properties of Co oxides by V component and the effect on the performance are investigated by in-situ XAS and ex-situ characterizations. The presence of the V component improves the reducibility of Co nanoparticles by modifying the interactions of Co with Al₂O₃. The catalytic performance results, combined with the characterizations, show that the increase in the surface concentration of metallic Co species by V component leads to the enhanced performance of alumina-supported Co-V oxide catalysts for PDH.