Hydroponic experiments were conducted to investigate dynamics of Na uptake and salt tolerance of 4 varieties of winter wheat different in genotype, i.e. Xiaoyan-6, NR-9405, Shaan-229 and RB-6. Results indicate that the sodium absorption dynamics of winter wheat could be divided into two phases.When salt concentration was low (-1), the parameters of Na uptake dynamics, V_max was 0.50, 0.30, 0.58 and 0.55 ⁺，mg g^-1h^-1, and K_m 18.50, 3.89, 70.90 and 30.68 mmol L^-1 of Xiaoyan-6, NR-9405, Shaan-229 and RB-6, respectively; But when salt concentration was high（> NaCl 80 mmol L^-1）, V_max was Na⁺1.81, 1.56, 2.11 and 2.11 mg g^-1h^-1 and K_m 107.20, 70.29, 121.06 and 102.67 mmol L^-1, respectively. In the low salt condition, the sodium exclusion rate was almost 90%, while in the high salt condition it was only 50%～60%. Sodium exclusion rate varied slightly with the genotypes of winter wheat, and it was 50% higher of Xiaoyan-6 and NR-9405 than of Shaan-229 and RB-6 in the low salt condition. On the contrary, the sodium absorption rate of Shaan-229 and RB-6 was 15% higher than that of Xiaoyan-6 and NR-9405, while the sodium exclusion rate was 10% lower in the high salt condition, The higher sodium absorption rate and the lower sodium exclusion rate in the high salt condition may be responsible for the salt sensitivity of Shaan-229 and RB-6.