Copper contaminated waste water treatment is one of the key techniques in introducing copper-based products in chip manufacture. Phytoremediation of copper is much cheaper compared with the traditional waste water treatment methods. This research investigated copper phytoremediation rate and limit with duckweed and water velvet. Although copper showed toxic effect to both duckweed and water velvet, duckweed and water velvet could accumulate copper in ther biomass to 100 – 370 folds of the initial copper supply concentration and consequently reduce the copper concentration in the solution to as low as 0.20 mg/L. The highest bioconcentration factors for duckweed and water velvet were 853 and 1472 respectively.