OBJECTIVE To study the preparation technology of chitohexose that is the main component, and to analyze the component of the preparing product. METHOD Chitosan was hydrolized with enzyme, then the chitosan oligomer was extrated with organic solvent, following by purifying the chitohexose by chromatograph method and detecting the chitosan oligomer component by HPLC. RESULTS The main component of the crude chitosan oligomer extract was 6 7 oligomer, the chitohexaose could be seperated by chromatograph.CONCLUSION The chitosan oligomer in which the main component was 6 7 oligomer could be produced by preparation technology.