One kind of adsorbent with a high adsorption capacity for anionic dyes was prepared using ionically and chemically cross-linked chitosan beads. A batch system was applied to study the adsorption of one acid dye (AAVN) and one reactive dye (RB4) in aqueous solutions by the cross-linked chitosan beads. The adsorption capacities (g/kg) had very large, values of 3362 (AAVN) and 3823 (RB4) at pH 3, 30degreesC, which were 6.6 (AAVN) and 6.0 (RB4) times that of those of the commercial activated carbon. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. The Langmuir model agreed very well with the experimental data (R-2 > 0.9980). The kinetics of adsorption for a single dye and the kinetics of removal of ADMI color value and COD for dyes in mixture solutions at different initial dye concentrations and pHs were evaluated by the pseudo first-order and second-order models. The data agreed very well with the pseudo second-order kinetic model. The study of competitive adsorption showed that the adsorption favored AAVN slightly in the experiments with higher dye concentrations.