The present invention relates to a monolith catalyst for carbon-dioxide/methane reforming and a method of manufacturing the same, and more particularly to a novel monolith catalyst for a reforming reaction having improved thermal durability, configured such that a sintering inhibiting layer is formed by coating the surface of a monolith support with at least one element selected from the group consisting of Group 2, 3, 6, 13, 15 and 16 elements among elements in Period 3 or higher and an active catalyst layer is formed on the sintering inhibiting layer, thereby preventing carbon deposition and catalyst deactivation due to deterioration even upon reaction at high temperatures.