Abstract: By using the vertical polyacrylamide gel electrophoresis,eight isozymes(i.e.,EST,LDH,MDH,GCDH, G6PD,ADH,SOD,GDH) from five tissues(i.e.,eye,muscle,liver,heart and kidney) of four species of Anguilla(i.e.,A.japonica,A.australis,A.Anguilla and A.rostrata) were analyzed.The results showed that GDH was not detected in all samples,while EST,LDH,MDH,GCDH,G6PD,ADH and SOD exhibited apparent tissue specificities.In the four species,the isozyme electrophorectograms showed similarities in their locus numbers,allele activities in a same tissue,significant differences among the tissues,and differences from species to species.By means of UPGMA,A.japonica was found to relate more closely to A.australis,while A.anguilla to A.rostrata.