Accumulation of cadmium (Cd) in a high biomass energy crop, switchgrass (Panicum virginatum L.), was studied using two soils (pH 5.6 and 7.3) treated with different rates of Cd (0, 20, 60 and 120 mg kg^-1 soil). The two eco-types of switchgrass cultivars, Alamo and Blackwell, growing on two soil moistures (saturated and unsaturated) were used for pot experiments. Plant seedlings germinated for three weeks were transferred into each pot with 1 kg Cd-treated soil. After two months of transplanting, pots were amended with ethylene diamine tetraacetic acid (EDTA) at 0.1 g kg^-1 soil or citric acid (CA) at 1 g kg^-1 soil. Control pots were not amended with any chelate. Harvest of the aboveground plant tissues was performed one month after chelate amendment. The harvested tissues were dried in an oven at 65^oC for 3 days to measure yields of dry mass and tissue Cd concentrations. In the results, there was a significant difference of tissue Cd concentrations among chelate amendments. The highest tissue Cd concentration of 70 mg kg^-1 in Alamo was found during the CA amendment but that of 200 mg kg^-1 in Blackwell was on the EDTA amendment. This indicated that the enhancement of phytoextraction with chelating agents was dependent upon cultivars. The dry weights of Alamo and Blackwell tissues harvested were correspondingly decreased with increasing the rates of Cd treatment. When Cd-treated rate was higher than 60 mg kg^-1, the significant decreases of dry weight were found. Therefore, the effect of Cd treatment on switchgrass was more pronounced at dry weight than at tissue Cd concentration.