目的 :研究壳聚糖羧甲基化条件、收率及产物的某些性质。方法 :在碱性条件下壳聚糖与一氯醋酸缩合成羧甲基壳聚糖 ,产物用等电点沉淀法分离纯化 ,同时测定了产物等电点。结果 :壳聚糖羧甲基化产率在 90 %～95 %之间。等电点为 7.17～ 7.5 6 ,除了溶液的 pH值在等电点外 ,产物在水溶液中完全溶解。 结论 :壳聚糖羧甲基化后 ,溶解性改变 ,扩大了其在医药领域的用途。 Objective: To study the conditions of carboxymethylation of chitosan, yield and some properties of the product. Methods: Under alkaline conditions, chitosan and monochloroacetic acid were condensed into carboxymethyl chitosan. The product was isolated and purified by isoelectric point precipitation and the isoelectric point of the product was determined. Results: The yield of carboxymethylated chitosan was between 90% and 95%. The isoelectric point of 7.17 ~ 7.5 6, in addition to the pH of the solution outside the isoelectric point, the product completely dissolved in aqueous solution. Conclusion: After carboxymethylation of chitosan, the solubility changes, expanding its use in the field of medicine.