Disclosed are a mesoporous composite oxide catalyst, a method for preparing the same and a method for synthesizing 1,3-butadidne using the same. The surface area is increased by introducing certain porous silica into preparation of a catalyst for synthesizing 1,3-butadiene, thereby improving a conversion ratio of normal-butene, and selectivity and yield of 1,3-butadiene, and providing economic efficiency from the viewpoint of decreasing an amount of used metal and reducing catalyst production cost.