Abstract:The effect of calcium on vigor of Zea mays L. seeds was studied. When seeds were treated with 0-10mmol/L concentrations of CaCl2, the germination percentage and vigor of seeds were increased. As Ca2+ concentration was more than 10mmol/L,the effects on seed viability and vigor decreased. The reasons that Ca2+ raised germination percentage and vigor of seeds might be due to the enhancing activities of amylases in embryo and endosperm,and the accelerating mobilization of stored reserves,e.g.starch and soluble proteins in endosperm. During seed germination, the exogenous EGTA and EDTA could drop seed vigor, but this inhibitory effect was partially removed by the addition of 2.5 and 10mmol/L Ca 2+.