A hollow golf club head 1 comprises a face portion 2 which includes a club face 2a for striking a ball, and a main body 3 extending rearward of the head from the face portion 2. The face Portion 2 is made of a low-specific-gravity material having a specific gravity of 4.0 or less. The main body 3 is provided in its face portion 2 side with a low stiffness zone 10 where the stiffness is locally reduced.