A sealing structure for sealing an inner side of a door glass in a door of an automobile includes a door trim having a downwardly extending trim flange facing toward the door glass; an inner door panel disposed adjacent the door trim with a clearance therebetween, the inner door panel having a downwardly extending panel flange facing the trim flange; an inner weather strip attached to the trim flange to form a seal between the door glass and the door trim; and an air sealing portion protruding from a lower edge of the inner weather strip. At least a part of the air sealing portion contacts the downwardly extending panel flange to shut-off or reduce air flow through the clearance.