The present invention provides a kind of spherical chitosan derivative as shown in lower formula (I):, wherein the spherical chitosan derivative has 10 to 500kDa molecular weight. The spherical chitosan derivative of the present invention can be fabricated to various forms according to the continuous application of Hou, more for properties such as inoxidizability, free radical scavenging ability and ultraviolet absorption abilities, Hou is continuous can to make face beautifying health keeping product, the drug cladding outer layer that antibacterial agent and controllable drug release or nanometer drug delivery carrier of what.本發明提供一種由下式(I)所示之幾丁聚醣衍生物：，其中，該幾丁聚醣衍生物具有10至500kDa之分子量。本發明之幾丁聚醣衍生物可依據後續應用製作成各種形式，更具備抗氧化性、自由基清除能力及紫外線吸收能力等性質，後續可用於製作美容保養品、抗菌劑及可控制藥物釋出之藥物包覆外層或奈米藥物傳輸載體。
