Abstract: The purification of serum immunoglobulin from the European eel(Anguilla anguilla) was carried out by means of euglobulin as well as ammonium sulfate precipitation.Purified by euglobulin precipitation,the resultant material analyzed by SDS-PAGE showed two distinct protein bands,indicating a higher purity of the A.anguilla serum immunoglobulin than that obtained by ammonium sulfate precipitation.The ELISA analysis showed that the serum immunoglobulin purifid by euglobulin precipitation had a higher antibody activity than that purified by ammonium sulfate precipitation.Furthermore,the Western-blot antibody activity test also yielded a positive result on the serum immunoglobulin purified by euglobulin precipitation.