A pot experiment was conducted to study effects of salt stress on emergence, growth, yield and absorption of Na⁺ and K⁺ of oil sunflower in order to clarify differences in response to salt stress between different varieties of oil sunflower. Results show that increased soil salt concentration decreased emergence rate, plant height, yield and biomass of oil sunflower, regardless of varieties, and the inhibitory effects were more apparent with Variety XK-6 than with Varieties LK-1 and FA15. Oil sunflower was much more tolerant to salt stress at the germination stage than at any later stages, and lower salt stress was somewhat beneficial to emergence and growth of oil sunflower. It was found that when the relative inhibition rate of salt stress reached over 40% at the seedling stage, the plant could not complete its life cycle, and when over 50%, it could not survive the budding or flowering stage. Na⁺ content in oil sunflower plants increased multiplied with increasing soil salt concentration, but K⁺ content did not change much, thus lowering K⁺/Na⁺ ratio drastically. So, proper salt concentration may promote K⁺ absorption by oil sunflower, but big differences exist between the varieties. The oil sunflower plants under the same salt stree followed an order of LK-1 < FA15 < XK-6 in Na⁺ content, and a reverse order in K⁺ content and K⁺/Na⁺ ratio. In terms of sensitivity of the plant at different stages to salt stress, a decreasing order of flowering stage and budding stage > emergence stage > maturity stage was worked out. Therefore, it seems to be a major mechanism of oil sunflower tolerating salt to reduce Na⁺ absorption, keep K⁺ stability and maintain higher K⁺/Na⁺ ratio in plants. The three varieties show a decreasing order of LK-1 > FA15 > XK-6 in salt tolerance.