Disclosed is a technique of narrowing a trim strip and improving ease of assembly. A boundary portion between upper and outer plate portions in the cross-section of a core is curved to have a large curvature. An outer portion of a glass run body is provided with an upper elastic protrusion engaging with an upper engagement portion of the trim strip. A gap is formed between an upper part of the outer portion of the glass run body and an upper portion of the trim strip. The gap allows the trim strip to move excessively toward the inside of a cabin.