A die assembly for extruding multilayer parisons which is excellent in controlling the respective thicknesses of the resin layers of parisons and comprises a parison programming shaft; a core pin which is attached to the lowermost end of the parison programming shaft; a mandrel which encircles the parison programming shaft; a plurality of control rings which are mounted on the mandrel; a plurality of sleeves which are installed around the mandrel; a housing which holds the above members; a controlling member to control the resin quantity of the outer layer of parisons; a die supporting member; and a die; and characterized in that the resin passage of the die assembly is regulated by each of the control ring together with an annular rib that is formed on the inner wall of the sleeve; by the controlling member together with the lowermost sleeve; and by the die together with the core pin.