Alginate, a well-known biopolymer, is universally applied for immobilization of microbial cells. Biosorption characteristics of lead by waste biomass of immobilized A. niger beads, used in fermentation industries to produce citric acid, were studied. The immobilized A. niger beads, prepared via capillary extrusion method using calcium chloride, were applied in the removal of lead. Pb uptake was the highest in A. niger beads cells grown for 3 days with medium producing citric acid (12% sucrose, 0.5% NH₄NO₃, 0.1% KH₂PO₄, and 0.025% MgSO₄). Lead uptake by the immobilized A. niger beads and free A. niger mycellia beads increased sharply with time. However, while uptake by the immobilized A. niger beads continued to increase slowly, that by free A. niger mycellia beads stopped after 30 min. The optimum pH and temperature of lead uptake were found to be 6 and 35℃, respectively. The maximum uptake of lead was achieved with 50∼100 beads and 50 ㎖ lead solution in a 250-㎖ Erlenmeyer flask, while, at over 100 beads, uptake of the lead decreased. The order of biosorption capacity for heavy metals was Pb$gt;Cu$gt;Cd. Pb uptake capacity of the immobilized A. niger beads treated with 0.1 M CaCl₂, 0.1 M NaOH, and 0.1 M KOH decreased compared to the untreated beads. On testing the desorption of Pb from the immobilized A. niger beads, re-uptake of Pb was found possible after desorption of the binding metal with 0.1 M HCl.