Abstract: Using the oxidation starch as raw material,the glucuronic acid was obtained by the processes of saccharification and fermentation. The conditions of saccharifying enzyme reaction and the yeast fermentation was studied,and the glucuronic acid of saccharification liquid and fermented liquid was regarded as evaluation standard. The results showed that the optimal conditions of saccharifing were as follows:reaction at 55 ℃ for12 h and amount of saccharifying enzyme was 1 m L in the 75 g of oxidation starch. The optimal conditions of fermentation were 25 m L saccharification liquid with 2.0 g yeast,temperature of 35 ℃ for 4 d. The research provided the theoretical guidance for the preparation of high content of glucuronic acid and the application of oxidized starch.