Abstract: In order to study the response of Betula nigra, Alnus glutinosa and Alnus crmastogyme to Cu stress and the difference of Cu tolerance among the three species, plant growth, changes of antioxidant system and Cu accumulation characteristics under different Cu concentrations of these three species were studied by the method of pot experiment. The results showed that (1) high Cu concentration (≥1 mmol/L) significantly reduced plant height, stem increment and biomass, which inhibited plant growth; (2) with the increase of Cu stress time, the activities of SOD, POD and CAT increased and then decreased, these three enzymatic activities in Alnus glutinosa were the strongest and the longest; (3) Cu accumulation in Alnus glutinosa and Alnus crmastogyme root, stem and leaf increased with the increase of Cu concentration, Cu accumulation in Betula nigra root and stem increased but Cu accumulation in leaf decreased with the increase of Cu concentration. In summary, plant growth of the three species was inhibited under high Cu concentration, they all showed Cu2 enrichment characteristics in root. The Cu tolerance of Alnus glutinosa was the strongest, Betula nigra had strong Cu resistance when the concentration of Cu was low, Alnus crmastogyme was relatively sensitive to Cu stress.