Chitosan and four cross-linked amino-starches (CAS) were employed to remove the acid dye acid black 1 (C. I. 20470) from aqueous solution. The optimum initial pH value is 3.0 and the adsorptions reach equilibrium after 3h. To describe the interactions of acid black 1 with different amino-polysaccharides, the linearized Langmuir and Freundlich isotherms were tested to fit the experimental data. The results indicate that the best-fit model is Langmuir isotherm and the mechanism is based on electrostatic attraction. The adsorption capacity of chitosan is highest amongst the amino-polysaccharides examined. The FT-IR spectra suggest that the amino groups of polysaccharides are protonated and the acid black 1 molecules were effectively adsorbed.