Abstract: A metallic hollow golf club head includes a sole face gently downwardly curved from a heel portion toward a toe portion, a generally rectangular protrusion having a predetermined width, the protrusion being downwardly protruded from an intermediate region of the sole face between the heel portion and the toe portion and extending backward from a face, and a recess formed at a widthwise-central portion of the protrusion and extending backward straightly with a predetermined width from a position apart from the face by a predetermined distance, thereby forming a pair of parallel rail portions at both sides of the recess. The recess is opened at a back face.