Abstract: 【OBJECTIVE】In order to enhance biologic activity of chitosan and to look for suitable supplement ferric dosage, chitosan-ferric complex was synthesized through the homogeneous reactions; 【METHOD】Their composition and structures were characterized by elementary analysis, UV spectra and IR spectra; 【RESULTS】It was found that the coordination was realized through binding of in chitosan with Fe3+ in the chitosan-ferric complex. The optimizing coordination condition of chitosan-ferric complex that the reaction was carried out under stirring at 25℃ and pH=1.8 for 8h. The adsorption isotherm and adsorption kinetics of chitosan for ferric ions were investigated and results were satisfied with the Langmuir-single-molecule-layer adsorption mechanism. The apparent adsorption velocity constant b is 4.969J/mg and the saturated adsorption capacity Q is 62.89mg/g at 298.15K. The UV spectra of the chitosan-ferric complex showed that new absorptive peaks appeared and the IR spectra of the chitosan-ferric complex showed that part of the characteristic adsorptive peaks of chitosan displaced. The spectral analysis indicated that the complex reactions took place mainly between the amino group(-NH2), the hydroxyl group(-OH), part of the acetylamino(-CONH2) of chitosan and Fe3+; 【CONCLUSION】It was hopeful to make pharmaceutical which people have chitosan-ferric complex to taken full advantage of from it, and chitosan-ferric complex become a kind of popular medicines with health protection.