Disclosed are a complex oxide catalyst for dehydrogenation, a method of preparing the same, and use thereof, wherein the catalyst includes a first transition metal selected from the group consisting of gallium, vanadium, chromium, manganese, molybdenum, and zinc, a hydrogen-activating metal including at least one selected from the group consisting of Groups 8, 9, 10, and 11 elements in a periodic table, and alumina, the amount of the first transition metal being 0.1 wt % to 20 wt %, the amount of the hydrogen-activating metal being 0.01 wt % to 2 wt %, based on the amount of the alumina, the first transition metal being loaded on the alumina, and the hydrogen-activating metal being surrounded by the alumina.