A heat shield structure of an exhaust manifold and a catalyst has a flange which is provided in a connecting portion connecting the exhaust manifold and catalyst and forms an open channel, an exhaust manifold heat shield member which covers an upper surface of the exhaust manifold, and a catalyst heat shield member which covers an upper surface of the catalyst. In the heat shield structure, an open side of the channel faces to the catalyst's side, a rear end of the exhaust manifold heat shield member is arranged on a vehicle body upper side of an end portion of the flange, and a front end of the catalyst heat shield member is arranged on a vehicle body floor side of the end portion of the flange. By this structure, heat from the exhaust manifold and catalyst can be efficiently released.