Identification of new hyperaccumulators is of great importance to successful phytoremediation of the environment contaminated with heavy metal.A new manganese hyperaccumulator plant, Phytolacca acinosa Roxb., was found growing in Southern China through field surveys on Mn mine tailings dumps and greenhouse experiments.This species has not only remarkable tolerance to Mn, but also an extraordinary capacity for this element.With the maximum Mn concentration in the leaf reaching 19 300 mg kg^-1, the plant grew well on Xiangtan Mn tailings dump with Mn concentration being as high as 114 000 mg kg^-1.Under hydroponic conditions, the manganese concentration in the plant leaves could reach as high as 36 380 mg kg^-1 with the bioaccumulation coefficient of 55 at a Mn supply level of 12.000 mmol L^-1.P.acinosa could grow quite well hydroponically with Mn supplied at a level of 8.000 mmol L^-1, although its biomass was less than the plant's in control with Mn supplied at 0.005 mmol L^-1.With the Mn concentration in the media increasing, the manganese concentration in the shoots increased, but the bioaccumulation coefficient gradually decreased.The total Mn accumulated in the aerial parts of the plant rose first and then declined.At the Mn concentration in the solution reached 5.000 mmol L^-1, the Mn accumulation in the aerial parts of the plant was the highest (258.2 mg plant^-1).Partitioning of Mn between the aerial parts and the roots showed that 87%~95% of Mn was transported into the former in all the treatments of the experiment, demonstrating the great capacity of the plant transporting Mn from the roots to the aerial parts.P.acinosa therefore offers great potent ial for use in phytoremediation of Mn-contaminated soils and waters.