To increase the sealability and the door closing property, and to improve the external appearance in an attaching structure wherein a door weather strip having a hollow seal section is attached to a sash.

For this attaching structure, an attaching section 2 of the sash 1 which forms the door of an automobile, a door weather strip 10 equipped with at least a base section 12 and the hollow seal section 11 is attached. The cabin internal side of the hollow seal section 11 is shaped into an arc section 11a, the cross section of which is formed into an approximately semi-circular shape. At the same time, the automobile external side end section of the hollow seal section 11 is connected with the base section 12 through a connecting section 13, the cross section of which has a short bar shape. A section of a body panel 20 with which the arm section 11a elastically comes into contact is made into a protruding curved section 21a which is projected into a curved shape. A section of the sash 1 with which the lower end section of the arc section 11a elastically comes into contact is made into a descending section 4 which is tilted downward.