A zoom lens system of compact size having a small number of lenses and a large field area is provided, comprising, in the following order from the object side, a first lens group G1 with a negative refractive power and a second lens group G2 with a positive refractive power, wherein zooming is executed by changing dead space between lens groups G1 and G2. The first lens group G1 comprises, in the following order from the object side, a first lens group front group G.sub.1F with a negative refractive power, and a first lens group rear group G.sub.1R with either a negative refractive power or a positive refractive power having at least one set of color erasable negative lens components L.sub.n and positive lens components L.sub.p. Focusing is executed by moving only front group G.sub.1F. For increased field angle, the first lens group G1 comprises a first subgroup L11 having a negative refractive power formed in a meniscus shape with a concave surface facing the image side, a second subgroup L12 with a negative refractive power having a cemented negative lens assembly with a negative lens and a positive lens cemented, and a third subgroup L13 having a positive refractive power with a convex side facing the object side.