Preparation of interpenetrating polymer network (IPN) gel beads for dye absorption was carried out by using simultaneous crosslinking method. First, sodium alginate (SA), 3-(methacrylamido) propyl trimethyl ammonium chloride (MAPTAC), and/or acrylarnide (AM), K2S2O8, and N,N'-methylenebisacrylamide (MBAM) were mixed in aqueous solution. The beads were prepared using K2S2O8 and MBAM as the initiator and crosslinking agent, respectively. Then, the solution was dropped into CaCl2 solution mixed with N,N,N',N'-tetramethylethylenediamine (TMEDA). The former was used as the crosslinking agent of alginate and the latter was used as the accelerator for the polymerization of monomer in the alginate solution. The gel bead composed of only alginate was also prepared to compare the properties with IPN gel bead. The components in IPN gel bead were examined by FTIR analysis. The factors effecting the particle size of alginate and IPN gel beads were investigated. In alginate gel bead, the concentration of solution affected the particle size, whereas type of monomer affected the particle size of IPN gel bead. The IPN gel bead had smooth surface (from SEM results), different from the alginate bead. Alginate content caused the swelling behavior of dried IPN beads. Cationic dye was absorbed by crosslinked alginate gel bead. The absorption of reactive dye by IPN gel bead was a result of its cationic charge. The absorption density of lPN gel beads was the reciprocal of the absorbent dosage. (c) 2006 Wiley Periodicals, Inc.