Abstract: With Canna indica ，Cyperus alternifolius and Brazilian milfoil as the test plants ，to simulate and study the tolerance of plants to Cu²⁺，different pH conditions on plant growth and enrichments of Cu²⁺. The results showed that three kinds of emergent plants have a strong tolerance for Cu²⁺ concentrations of 2、4 、6 mg/L. After 21 days test ，the Cu²⁺ enrichments of three kinds of plants were maximum in 6mg/L ，respectively were 208. 562 mg/kg （Canna indica），332. 453 mg/kg （Cyperus alternifolius） and 201. 373 mg/kg（Brazilian milfoil）. The Cu²⁺ enrichments of Canna indica and Brazilian milfoil were maximum in water with pH = 5（234. 636 mg/kg and 168. 957 mg/kg），while Cyperus alternifolius was maximum at pH = 7（246. 652mg/kg），and the roots of Canna indica and Cyperus alternifolius on Cu²⁺ accumulation were far stronger than the stems and leaves，the transfer coefficient of Cyperus alternifolius was higher than Canna indica，thus Cyperus alternifolius is propitious to recover Cu²⁺.

Key words: emergent aquatic plant, Cu²⁺, enrichment capacity, transfer coefficient