in summary,new chitosan derivatives, chitosan-oxanordornadienes, were successfully synthesized for metal free click chemisty. By varying the reaction conditions, a chitosan derivative with a degree of 08% oxanordornadiene on chitosan could be obtained (CS-3). In addition, the ligation process and the selectivity of the reaction were studied. Therefore the components of the reaction were simply mixed at room temperature and the products could be obtained without any further purification steps. Consequently, these chitosan oxanorbornadiene derivatives combined with the metal-free click chemistry provide a simple alternative for the coupling of various azido-modified substrates to polymer and facilitate their application in the biomedical field.