Abstract: With the EDTA (ethylene diamine tetraacetic acid) and H2SO4 (sulfuric acid) solutions both used as the extractants to extract the polysaccharide from EPS (extracellular polymeric substance) via bioleaching, the extracting process includes four steps, i.e., collecting thallus by centrifugation, leaching polysaccharide with extractants, separating polysaccharide by centrifugation and filtering out thallus. The extracted polysaccharide content was measured by phenol-sulfuric acid. The results showed that the extractant EDTA is superior to H2SO4 in extraction effect if their mass fractions are the same, and the 3% EDTA is regarded as the best one in our tests, by which the content of extracted polysaccharide can be up to 0.017 mg·mL^-1. The whole extracting process has the advantages of simple reagent required, easy to operate and less interfering factors.