Abstract: Wheats were treated with the Hoagland solutions respectively with NaCl、Na 2SO 4 and Na 2CO 3 at the concentrations of 0,50,100,150 and 200?mmol/L for 6 days. Results showed that the contents of H 2O 2 in the treated ones increased compared with the control while the contents of chlorophyll reduced. The contents of DNA and RNA decreased with the increased concentrations of the Na salt solutions and RNA decreased rapidly while DNA maintained relatively stable. The DNase activity increased a little under the weak stress and declined under the strong one. The RNase activity decreased with the increased concentrations of the Na salt solutions. The stress effect of NaCl was the least while that of Na 2CO 3 was the greatest. Results obtained in the study also showed that RNase was more sensible to the stress of Na salt than DNase and the Na salt stress affected RNA more significantly than DNA.