A weather strip 100 mounted along a circumferential edge of a door opening of an automobile body 60 comprises: an installation base member 30 having a substantially U-shape in cross-section; and a hollow seal member 40 provided on an outer-cabin side of the installation base member 30, which makes elastic contact with a protrudingly curved surface 70a having a substantially U-shape in cross-section of the door 70; in which the hollow seal member 40 includes: a first hollow wall 41 having a substantially reversed V-shape in cross-section and a second hollow wall 42 having a substantially V-shape in cross-section, which are connected with each other; a seal wall 42Y swelled and curved toward an inner side of the hollow seal member 40; and a protrusion 43 protrudingly provided toward the outer-cabin side in succession to the seal wall 42Y, which makes elastic contact with the protrudingly curved surface 70a.