A weather strip has a base portion and seal lips. The base portion has a base bottom portion attached to a door frame, side wall portions extending from substantially opposite sides of the base bottom portion, and a bridge portion connecting the opposite side wall portions. A hollow portion is formed by these portions. An exterior-side seal lip is provided to extend from a substantially border portion between the exterior-side side wall portion and the bridge portion. An interior-side seal lip is provided to extend from the bridge portion more interior than the exterior-side seal lip. In the bridge portion, the opposite sides of the root portion of the interior-side seal lip are formed into thin portions respectively. Thus, when the door is closed, even if the gap is narrowed, the interior-side seal lip is bent and the bridge portion is deformed easily in the thin portions so that the repulsion stress is restrained from increasing conspicuously.