Exopolysaccharide-producing bacteria were isolated from the soil according to the mucoid secretion around the colony,the yield of extracellular polysaccharide was determined by phenol-sulfuric acid method.The exopolysaccharide-producing strain LE-3 was identified based on morphological characteristics,Biolog analysis and 16S rDNA sequence analysis.The crude extracellular polysaccharide isolated from strain LE-3 was purified by Sevage method,dialysis and CM-Sepharose FF chromatography,DEAE-Sepharose FF chromatography and Sephacryl S-200HR chromatography.The monosaccharide composition of the polysaccharide was analyzed by FT-IR,TLC and HPLC.Results showed that among the 26 strains isolated from soil on the basis of the first screening standard,there were 3 strains that could produce exopolysaccharide more than 5 g/L,and the exopolysaccharide yield of strain LE-3 was 5.29 g/L.Strain LE-3 was identified as Bacillus amyloliquefaciens subsp. amyloliquefaciens based on morphological characteristics,Biolog analysis and 16S rDNA sequence analysis.A single component of exopolysaccharide isolated from strain LE-3 was obtained after deproteinization,dialysis and chromatography.Finally,the polysaccharide was determined to be a fructan by FT-IR,TLC and HPLC analysis.