Greenhouse experiment were conducted on two barley varieties (Giza 123 (salt tolerance) and Giza 125 (salt sensitive)) . Plants were treated with 25, 50 ppm paclobutrazol (PP₃₃₃) or 10 ppm abscisic acid (ABA) as foliar spray 3 weeks after sowing date. Four levels of NaCl salinity (0, 2500, 5000, 10000 ppm) were used two days after plant growth regulator treatments. The results indicated that, the harmful effect of salt stress was more clear on variety Giza 125 than that found on variety Giza 123. Where, the decrease of plant height and shoot fresh weight by the highest NaCl level were obvious as compared with control treatment. The reduction of two parameters reached 40% and 69% in Giza 123 as well as 66% and 81% in Giza 125, respectively. However, treatment of plant growth regulators significantly reduced the injury effect of salt stress. The ABA treatment had a better effect than that obtained by paclobutrazol ones. Also, the negative effect of salt stress on grain yield was significantly improved by application of plant growth regulators. However, regression analysis between grain yield and some chemical constituents in barley leaves, illustrated that, the K/Na ratio in barley leaves had the highest R² value (0.88) with grain yield whereas R² values of chlorophyll and proline contents in leaves gave 0.33 and 0.71 respectively. So, the negative effect of salinity on barley may occurr due to decrease of K uptake and increasing of Na uptake. Consequently K/Na ratio was decreased. So improving of barley growth and yield could be achieved by ABA application. This work aimed to determine the best physiological parameter related to salt stress in barley plants may be due to the rebalance of K/Na ratio in leaves.