Abstract: This paper reports the ultrastructure of mesophyll cells of wheat seedlings in NaCl. After three days, the ultrastructure of mesophyll cells of wheat seedlings were observated. The results showed that the ultrastructure of mitochondrias had various changes, the mitochondria membrane and cristae swelled. However, Ultrastructure of chloroplast envelope and lamellae were still intact, but paralled arrangement of some lamellae in chloroplast was altered. The ultrastructure of niclei and cell wall did not take place any changes.