Abstract: Effects of cadmium on alfalfa seed germination and growth were studied.The results show that the effects of cadmium on the germination rate of seeds are not significant when Cd²⁺ concentration ranges from 0mg/kg to 10mg/kg,but the effects on the germinating energy are significant.Once Cd²⁺ concentration is up to 30mg/kg,the germination of seeds is evidently inhibited with significantly decreased germinating energy and rate.Cd²⁺ with different concentrations all can inhibit the growth of buds and roots significantly,and has stronger inhibition on root than on plumule.Basically,with the increase of Cd²⁺ concentration,the inhibiting effect is enforced,and the index of seed vigor is decreased.The growth of seedlings is almost inhibited completely while Cd²⁺ concentration is up to 50mg/kg.