Abstract: Using tryptone soya broth medium,the culture conditions of Edwardsiella tarda(ETY) were optimized by a single factor and an orthogonal test to enhance the cell concentration.The results showed that the optimized medium contained 3.0 g of glucose,10.0 g of tryptone,10.0 g of peptone,2.50 g of K2HPO4 and 5.0 g of NaCl per liter.And,the most favorable fermentation conditions were at 25℃,with an initial pH of 7.5,on a stirring speed of 200 rmin-1 and with the inoculating ratio of 8%.Compared with the control,the cell concentration of ETY could be improved from 5.200×109cfumL-1 to 1.575×1010cfumL-1,i.e.,3 times increase.At the same time,the cost of liquid medium was reduced by 41.36% compared to the conventional formulation.