Abstract: The contents of four heavy metal elements including Cu, Pb, Zn and Ni in 30 weed species collected from the sewage area near a smeltery were determined and analyzed.The results showed that the organs followed an order as roots>leaves>stems based on their average concentrations of four elements.The elements ranked as Cu >Zn>Ni>Pb according to their concentrations in weeds, while the accumulation coefficients were in order of Zn>Cu>Pb>Ni in weeds.The accumulation coefficients of Cu in the roots of Alopecurus aequalis, Zizania latifolia, Bidens pilosa, Ludzvigia prostrate, Paspalum distichum and Phragmites australis were 2.54, 2.69, 4.82,10.74, 7.33 and 4.60, respectively.The roots of these weeds had high enriching abilities of Cu.Cu concentrations in some weeds were as follow: roots of Alopecurus aequalis 813.4, roots of Paspalum distichum 1 338, roots of Ludwigia prostrate 1 959.65, roots of Phragmites australis 840.1, roots of Bidens pilosa 1 066.6, the underground parts of Pteris multifida 2 030 and leaves of Conyza canadensis 334.5 mg穔g^-1.The leaves of Ploygonum hydropiper exhibited high abilities of accumulation of Pb.Ludxvigia prostrate, Cnidium monnieri, Veronica didyma and Artemisia lavandulaefolia showed high accumulation abilities of Zn.Little correlation between the heavy metal element contents of weeds and soils was found from regression analysis.Ludvuigia prostrate is very useful in the restoration of Cu and Zn sewage polluted area.

Key words: Spatial diversity index, Wildlife, Habitat pattern, Liaohe Delta