A biaxially drawn, blow-molded bottle and its preform comprise at least a layer of a gas barrier material laminated inside the PET resin layers, a functional portion having a screw thread raised spirally in the upper portion of neck and also having a stop ring disposed under the screw thread, and a neck ring disposed at the lower end of the neck. In these preform and bottle, the leading edge of the gas barrier layer is positioned at a half height of the neck ring where the most advanced front of the leading edge neither reaches a half height of the stop ring nor extends to the functional portion. It is intended here that the neck would not be affected by the shrinking deformation caused by the existence of the gas barrier layer in the functional portion of the neck, which is treated for thermal crystallization.