A hollow weather strip which is excellent in an external appearance is provided. The weather strip comprises an extrusion portion having a given width, a mold portion connected to an end side of said extrusion portion. The mold portion has a slot at a back surface thereof and has a width which is larger than the width of the extrusion portion by a width of the slit. The extrusion portion has a substantially V-shape spread slit provided on an end back surface thereof, and the slit is continuous from the slot and is consecutively reduced in a width as said V-shaped spread slit recedes from a position where the extrusion portion and the mold portion are connected to each other.