Abstract: In this study, dissolved organic matter (DOM) was extracted from earthworm casts and from the cattle manure with which the earthworms were fed, and a water culture experiment was conducted to study the effects of the DOM on the copper (Cu²⁺) absorption by ryegrass in the presence of different concentration Cu²⁺(0, 5 and 10 mg ·L^-1). With the increasing concentration of Cu²⁺ in the medium, there was a gradual decrease in the dry mass of ryegrass shoots and roots and in the root length, surface area, volume, and tip number. In the presence of medium Cu²⁺, DOM increased the biomass of shoots and roots and the root length, surface area, volume, and tip number significantly. DOM reduced the Cu²⁺concentration in roots, promoted the Cu²⁺ translocation from roots to shoots, and significantly increased the Cu²⁺ accumulation in shoots. The DOM from earthworm casts had better effects than that from cattle manure, and high concentration DOM had better effects than low concentration DOM.