A sub-lip is provided on an interior side wall portion of a main body having a U-shaped cross section in a vertical section of a glass run. The sub-lip extends from the interior side wall portion of the main body while inclined towards an inner side of a glass opening. A projecting length of the sub-lip is set such that a distal end portion of the sub-lip is brought into contact with a back surface of an interior seal lip when a door glass is inserted into an inner space of the main body.