Abstract: Abstract :In order to learn the effect of salt stress on tomato fruit quality and yield，the results will be helpful in theory for breeding and select salt tolerance variety in the future. Three cultivated tomato varieties “SJX”，“WFS” and “HDL” were chosen in the experiments，treated with different concentration of Na2SO4 during flower and fruit stage. The results indicated that tomato fresh weight per fruit and yield of each plants decreased when concentration of Na2SO4 increased，the firmness of tomato fruit went up at high concentration salinity while went down at low concentration. The content of total soluble matter of the three tomato changed with a single apex curve when treated with salinity concentration varied from 0.1 to 0.4 mol/L, Soluble sugar and organic acid in fruit increased compared with the contrast，the ratio of sugar to acid decreased. The yield of tomato fruit decreased under salt stress of Na2SO4，the firmness, the content of total soluble matter and organic acid in tomato fruit changed with the treatments，which lead to changes of quality of tomato fruit.