As biosorbent used Sphaerotilus natans, influencing factors on removal of Pb2+ were investigated such as ratio of the biomass and lead, pH, temperature and time of adsorption. The results show that Sphaerotilus natans has good effect on adsorption of Pb2+. The process of adsorption reached equilibrium in 10 minutes. Temperature has no significant effect on the adsorption. Removal of Pb2+ approached to 100% under the condition of pH 5.5, 0.6 g/L and c0 < or =20 mg/L. The maximum adsorption amount was 2.1 mmol/g dry biomass . The adsorption was fitted with Freundlich isotherm adsorption equation under the concentration of Pb2+ 0-60 mg/L. HCI and EDTA can desorb the Pb2+ from the bacteria effectively.