Abstract: Experiment was conducted to evaluate the effect of different concentrations of Cu2+， Ag+， Cr6+ in soil on earthworms. Earthworms were cultivated in different soil samples containing 0， 5， 50， 100 mg·kg-1 Cu2+， Ag+， Cr6+， respectively. After 7 d， metallothionein （MT） content and GSH\|Px enzyme activity were determined. It was shown that MT content in earthworm was higher under 5 or 50 mg·kg-1 Cr6+ treatment compared to the control， while it was lower under 100 mg·kg-1 Cr6+ treatment compared to the control. Under 50 or 100 mg·kg-1 Cu2+ treatment， MT content in earthworms was significantly lower than that of control. Under 5， 50 and 100 mg·kg-1 Cr6+ or Ag+ treatment， the enzyme activity of GSH\|Px was significantly higher than control. For Cu2+， the enzyme activity of GSH\|Px was significantly higher than the control under 5 or 50 mg·kg-1 treatment. Among these heavy metals， Cr6+ exhibited greater influence on MT content and GSH\|Px activity in earthworms than that of Cu2+ and Ag+.

Key words: earthworms, Cu2+, Ag+, Cr6+, metallothionein, glutathione peroxidase