bacterium LV-1 which isolated from soil sample were studied bacterium was isolated by serial dilution method, the effects of carbon source, nitrogen source, the initial pH and temperature on producing polysaccharide by it were discussed to confirm the optimum fermentation conditions. [ Result] The physicochemical properties showed that the polysaccharide was water-soluble, but insoluble in organic solvents including ethanol, butanol, and chloroform. It was neutral polysaccharide with negative charge and without reducing terminal. The pH of its solution was pH =7.5. There were no protein, fructose, uronic acid, sulphate and starch-like structure included in po/ysacchadde molecules. The optimum fermentation conditions for po/ysaccharide produc- tion were 3% mannitol as carbon source, 0.25% yeast extract as nitrogen source, culture temperature 28 ~(3 and pH =7.5. [Coadu^en] The re- search could provide basis for development and utilization of LV-1 and industrialized production of mucopolysaccharide.