Abstract: The influences of magnetized water on contents of N, P, K, Ca and Mg in cucumber leaves in protected field of winter-spring was researched, the cultivars was Hanxiu and Lushang dingfeng No.1. The results showed as follows: During the growing period of cucumber leaves, the variation of N and P contents were one-peak pattern curve, and that of k, Ca and Mg were two-peak pattern curve .After treated by magnetized water, there were very remarkable differences in contents of P and Mg in Hanxiu leaves, remarkable difference in Ca content, and no significant differences in N and K contents. For Lusheng dingfeng No.1, only Mg content had very remarkable difference between two treatments, the rest were not significant.