In order to clarify the effect of inositol on the anti-aging in yeast,0. 5g /L of exogenous inositol was added to the fermentation medium during the sub-culturing process of Saccharomyces cerevisiae 2144 and the dynamic of growth rate,fermentablity of glucose and flocculation rates were monitored. In parallel,the content of super oxygen anion( O2-·) and the activities of antioxidant enzymes were also determined. The results showed that the rate of flocculation and the content of O2-· were reduced 23. 04% and 26. 19% respectively in 15th generation fermentations with 0. 5g / L of exogenous inositol compared to those in the groups without inositol. Furthermore,the maximum activities value of superoxide dismutase( SOD),catalase( CAT) and peroxidase( POD) were increased 16. 39%,19. 67% and 42. 86% respectively,and the maximum values were delayed for two generations. Those results indicated that the exogenous inositol would enhance antioxidant ability in sub-culture of yeast and thereby improve the anti-aging of the cell.