Barley was grown in zinc-polluted soils in order to investigate zinc toxicity and the zinc-supplying ability of such soils, as well as to study the effects of high zinc content on the chemical composition of barley. The application of zinc increased the zinc content of barley from 320 to 737, 191 to 379, and 233 to 489 ppm in soils A, B, and C, respectively, but failed to produce severe toxicity. A high correlation (0.999) between “A” values and zinc determined by chemical method indicates that the “A” value is a good criteron for assessing the zinc-supplying ability of soils. Except for Mn (where the concentration in the barley plants increased with increased level of added zinc), the concentrations of Fe, Cu, P, K, Ca, and Mg were not affected by zinc application, which indicates that the interactions between Zn and other cations are governed by their relative concentrations in the growth medium.