The novel lectin was isolated from the mycelium of Hypoxylon sp. by phosphoric acid buffer, precipitation of 20%-70% (NH4)2SO4, DEAE-Cellulose and Sephadex G-100 chromatography. It turned out to be a single band in PAGE. SDS-PAGE showed the subunit of Hypoxylon sp. lectin (HSL) was 15.9 kD. HSL was glycoprotein through dyed by Periodic acid-Schiff reaction, and the carbohydrate content was 15.5%. β-Elimination revealed the bond between the polysaccharide and the protein of HSL was O-type glucopeptide one. The HSL could agglutinate erythocytes regardless of blood type or animal species. HSL was less thermostable, and the hemagglutinating activity declined obviously after being heated 10 min under 50°C. The HSL was alkali-stable but not acid-stable. Its activity was affected by Al3+, Fe3+, Ca2+ and Zn2+. The hemagglutination of the lectin on mouse erythrocytes was inhibited by galactose and lactose among the sugars tested.