A pot experiment was conducted to study the effects of different concentrations of melatonin soaking on the growth and cadmium accumulation of pea seedlings. The results showed that the doses of 50, 100, 150 and 200 μmol/L melatonin treatments increased the biomasses, water contents, photosynthetic pigment contents and antioxidant enzyme activities of pea seedlings compared with the control, and cadmium contents in pea seedlings reduced significantly. When the dose of melatonin was 200 μmol/L, the biomasses and photosynthetic pigment contents of pea seedlings reached the maxima, and cadmium contents in roots and shoots of pea seedlings were the minima of 6.72 and 0.104 mg/kg, reduced by 20.28% and 46.39% respectively compared with the control. Therefore, melatonin soaking could promote the growth of pea seedlings and reduce cadmium uptake, and the best dose of melatonin is 200 μmol/L.