[Problem] To provide a light-weight air conditioning duct for vehicle that is light in weight and excellent in mechanical strength.[Solution] The present invention is directed to a light-weight air conditioning duct for vehicle 1 for letting conditioned air supplied from an air conditioning unit pass through to a desired location, the duct being obtained by blow-molding a mixed resin including a polypropylene-based resin for foaming and a hydrogenated styrene-based thermoplastic elastomer, and the duct having an Izod impact strength equal to or larger than 10 J/m at −20 degrees Celsius.