A golf bag is provided with a lower frame, an inner frame, two positioning support members, an upper frame, an outer support member and a cover. The two slots are provided at two opposite sides of the inner frame, the magnetic member is disposed on the inner surface of each of the slots, the first receiving cavities are formed on the lower frame, the magnetic end of the positioning support members are inserted in the slots and attracted by the magnetic members, and another end of the positioning support members are inserted in the first receiving cavities, all these arrangements contribute to strengthening the connection between the inner and lower frames, consequently stabilizing the structure of the golf bag.