An anti-viral protein was isolated from Megalobrama amblycephala serum by affinity chromatography on a column of Sepharose 4B-GCHV structure protein .Depending on exogenous β-mercaptanethanol , the isolated anti-viral protein could agglutinate rabbit erythrocytes treated by trypsin .Galactose was the most active inhibitor to the protein in hemagglutination inhibition test , and mannose had less activity than that of galactose .The molecular weight of the protein was 240 000 in PG-PAGE and SDS-PG-PAGE demonstrated that it had a subunit structure consisting of a single component with a molecular weight of 15 000 .The anti-viral protein was designated anti-viral galectin-like protein of M .amblycephala .After treatment with rabbit anti-serum, the rest serum of M .amblycephala lost it' s anti-viral and hemagglutination activity completely .The amino acid sequence of N-end of the galectin-like protein was Lys-Val-Asn-Leu-Asp-Glu-Lys-Cys-Pro-Phe , and no protein with the homologous amino acid sequence was found in the GenBank .