In order to research on changing of K+,Na+of sunflower under salinity stress. In the fields and in-door potted environment,the changing of K+and Na+of sunflower under different concentrations of salinity stress was studied. The results showed that:with increasing of soil salinity,sodium content of roots,stems,and leaf of sun-flower increased,content of potassium reduced,and thus the K+/Na+was significantly decreased;value of K+/Na+ of leaves was higher than of stems than of roots,and the value of K+/Na+of leaves was significantly different from of roots and of stems. As salinity stress enhancement,the K+/Na+of various organs decreased differently,especially the ratio of potassium and sodium decreased significantly. Different varieties had different content of potassium and sodium,the ratio of potassium and sodium of salt-tolerant varieties decreased less under salinity stress. Sodium of oil sunflower absorption accumulated in the roots,mechanism of refusing salt that prevented sodium transporting to the aboveground is one of the main reason of sunflower with strong salt tolerance.