Objectives To discuss the feasibility of using daphnia pulex as a marker of monitoring Cd²⁺pollution in water surroundings.

Methods The growth and activities of T-SOD, CAT and GST in daphnia pulex was used for monitoring the effect of Cd²⁺ in water under laboratory conditions.

Results Under sub-lethal concentration of cadmium in water, the growth of daphnia pulex was promoted at low Cd²⁺ (0.0125 mg/L) in short times, while inhibited prominently at moderate and high Cd²⁺ (0.025 mg/L and 0.05 mg/L). The activities of T-SOD, CAT and GST in all treated groups were decreased at 12 h compared with the control group; the activities in low and moderate Cd²⁺ groups were increased at first and then downward with longer exposure time (in 24~72h), while the activities in high Cd²⁺ groups were lower than that in the control group all the time.

Conclusions It is practicable of using daphnia pulex as a marker for monitoring Cd²⁺ pollution in water surroundings.