Abstract: This invention relates to a process for producing exopolysaccharide from submerged mycelial culture of mushroom and more particularly, to the process for improving the exopolysaccharide production from the mycelia using the different bistage pH control technique comprising the steps of; (1) a process for the production of mycelia whose pH conditions in a batch medium are kept constant at 2 to 6 at the initial pH, while adding ammonium ion to the medium, and (2) a process for the production of exopolysaccharides whose pH conditions in a batch medium containing the mycelia are adjusted to 3 to 7. According to this invention, the optimized mycelial morphology and rheological properties in the culture media can lead to EPS production in more efficient and stable manner.