The paper preliminarily discusses the effects of cadmium pollution on the alkaline phosphatase of mussel, mytilue viridid. The results show the cadmium pollution has a inhibition on the alkaline phosphatase, and the degree of inhibition rises with the increases of concerntration if cadmium in seawater. When the concentration is within the range of 1-500 ppb, the percentage of inhibited emzyme has a linear relationship with the logarithm of cadmium concentration. The results also prove that the salinity may increase the effects of cadmium on emzyme. The inhibition which may be indirect or secondary effects is reversible.Mussels play a purification role in the waste water containing cadmium, the purification rate of which may as high as 125 mg Cd2+ gram (mussel)/day. This is a prospective method in purification and removing of cadmium.The study of effects of cadmium pollution on the alkaline phosphatase of mussel shows that in the study of effects of pollutants on aquatic organisms, biochemical index may The paper preliminarily discusses the effects of cadmium pollution on the alkaline phosphatase of mussel, mytilue viridid. The results show the cadmium pollution has a inhibition on the alkaline phosphatase, and the degree of inhibition rises with the increases of concerntration if cadmium in seawater. When the concentration of within the range of 1-500 ppb, the percentage of inhibited emzyme has a linear relationship with the logarithm of cadmium concentration. The results also prove that the salinity may increase the effects of cadmium on emzyme. The inhibition which may be indirect or secondary effects are reversible. Mussels play a purification role in the waste water containing cadmium, the purification rate of which may as high as 125 mg Cd2 + gram (mussel) / day. This is a prospective method in purification and removing of cadmium. study of effects of cadmium pollution on the alkaline phosphatase of mussel shows that in the study of effects of pollutants on aquatic organisms, bioc hemical index may