Abstract: Improving the technique of culture separation, the strain Sphaerotilus natans was isolated from a kind of wastewater. A test was done for its colonial morphology, biochemical and physiological features, growth curve, culture preservation and biosorption of heavy metals. The strain was identified to be of Sphaerotilus as the 14th group of sheathed bacteria. Testing results showed that Sphaerotilus natans has excellent effect on adsorption of Pb²⁺. The biosorption can reach equilibrium within 10 minutes. The removal rate of Pb²⁺ approaches to 100% under conditions that pH=5.5, drying biomass =0.6 g/L and initial Pb mass concentration ρ0&le20 mg/L.