Abstract: The fermentation conditions of marine bacterium Lysinibacillus xylanilyticus strain JZ008 were optimized with single factor methodology. The optimal fermentation conditions were set at temperature 35℃, pH 7.5, inoculation quantity 3.0% (V/V) and volume of liquid 50 cm³/250 cm³. After optimization, the amount of bacterium reached 2.01×10⁸ CFU/cm³, which was 40.6% higher than that before optimization. Algae oligosaccharide is helpful for the growth of bacterium. The viable count of fermenlatin broth added 5.0g/dm³ algae oligosaccharide reached 2.51 times comparing to the control group. The biosorption characteristics of Cd²⁺, Cr³⁺, Cu²⁺ by strain JZ008 were studied. The results showed that the biosorption rate of three heavy metals was obvious in solution, the adsorption rate reached 95.6%, 96.4% and 87.0% after 20 days, respectively. The results also showed that the biosorption rate of the heavy metals was obvious in soils mixed with algae oligosaccharide and strain JZ008. The adsorption rate reached 82.5%, 82.0% and 86.9% after 60 days, respectively. The excellent biosorption characteristics of the strain laid a foundation for the further development and application of Lysinibacillus xylanilyticus in the remediation of heavy metals.