The study included two parts: First, 10 maize cultivars which were mainly cultivated in coastal area of province under seawater stress were studied. We studied the physiological and biochemical charge of the SOD and POD activity, soluble protein content, free proline contents , malondialdehyde(MDA)content and photosynthetic pigment content, photosynthetic rate of maize leaves, and the water concent of maize different apparatus , and we investigated the charge of ions of CI- concent, Na~+ concent, K~+ concen...