A zoom lens system comprising:- a plurality of lens groups (G1-G4) aligned on an optical axis; wherein at least one lens group of said plurality of lens groups is moveable in the direction of the optical axis to perform zooming; wherein a specified lens group of said plurality of lens groups (G1-G4) includes:- a focusing lens group (G1b, G1b') which is moveable in the optical axis direction in a focusing operation, and at least one lens element (G1a, G1a') other than said focusing lens group, wherein the distance between the focusing lens group and said at least one lens element remains unchanged during zooming; wherein the zoom lens system is operable in:- a normal photography mode in which focusing is carried out from infinity through to a predetermined photographing distance by moving said focusing lens group (G1b, G1b') of said specified lens group in an optical axis direction; and a shifting mode in which the zoom lens system is shifted from said normal photography mode to a macro photography mode by moving said at least one lens element (G1a, G1a') of said specified lens group when focusing on an object at a photographing distance that is shorter than said predetermined photographing distance of said normal photography mode; wherein, when said zoom lens system is in said macro photography mode, focusing is carried out from said predetermined photographing distance through to a minimum photographing distance by continuously moving said focusing lens group (G1b, G1b') in an optical axis direction. a plurality of lens groups (G1-G4) aligned on an optical axis; wherein at least one lens group of said plurality of lens groups is moveable in the direction of the optical axis to perform zooming; wherein a specified lens group of said plurality of lens groups (G1-G4) includes:- a focusing lens group (G1b, G1b') which is moveable in the optical axis direction in a focusing operation, and at least one lens element (G1a, G1a') other than said focusing lens group, wherein the distance between the focusing lens group and said at least one lens element remains unchanged during zooming; a focusing lens group (G1b, G1b') which is moveable in the optical axis direction in a focusing operation, and at least one lens element (G1a, G1a') other than said focusing lens group, wherein the distance between the focusing lens group and said at least one lens element remains unchanged during zooming; wherein the zoom lens system is operable in:- a normal photography mode in which focusing is carried out from infinity through to a predetermined photographing distance by moving said focusing lens group (G1b, G1b') of said specified lens group in an optical axis direction; and a shifting mode in which the zoom lens system is shifted from said normal photography mode to a macro photography mode by moving said at least one lens element (G1a, G1a') of said specified lens group when focusing on an object at a photographing distance that is shorter than said predetermined photographing distance of said normal photography mode; wherein, when said zoom lens system is in said macro photography mode, focusing is carried out from said predetermined photographing distance through to a minimum photographing distance by continuously moving said focusing lens group (G1b, G1b') in an optical axis direction. a normal photography mode in which focusing is carried out from infinity through to a predetermined photographing distance by moving said focusing lens group (G1b, G1b') of said specified lens group in an optical axis direction; and a shifting mode in which the zoom lens system is shifted from said normal photography mode to a macro photography mode by moving said at least one lens element (G1a, G1a') of said specified lens group when focusing on an object at a photographing distance that is shorter than said predetermined photographing distance of said normal photography mode; wherein, when said zoom lens system is in said macro photography mode, focusing is carried out from said predetermined photographing distance through to a minimum photographing distance by continuously moving said focusing lens group (G1b, G1b') in an optical axis direction.