Effects of acidity on copper speciation in soil solution and relations of copper forms with ryegrass growth and copper uptake were studied.It was found that acidity affected copper speciation severely in soil solution.With the increase in soil acidity soil copper forms of soluble,ionic and DOC(dissolved organic carbon) bounded fractions all increased and with the increase in copper treatment the effect of acidity was more significant.Acidity also affected ryegrass copper uptake.With increase in acidity ryegrass copper uptake increased and the differences of two soils were significant when copper treatment was higher than 50 mg/kg.Ryegrass biomass had significant negative correlations with ryegrass copper,soluble copper,DOCCu and IONICCu.Soil DOC content which was also affected by acidity increased with acidity decrease.