Abstract:Lectin was purified from Apotichopus japonicus Selenka by extraction with PBS, followed by 20% - 75% ammonium sulfate fractionation and molecular sieve chromatography on the Sephadex G-200 . The Lectin had a molecular weight of 85 652 Da on Sephadex G-200 and contained saccharied of 20.9%. The lectin was nonspecific in agglutination for any type of human erythrocytes, and the hemagglutinating activity for human( A) was the highest, the agglutination for chicken was the highest, among erythrocytes of humans( A, B, AB, O), rabbits, mouse and common carp. The hem,agglutinating activity for rabbit could not be inhibited by D-galactose, glucose, sucrose, mannan, gamma-globulin(human), but inhibited by bovine-thyroglobulin. The minimum inhibitory concentration was 1.55 mg?mL^-1. The hemagglutinating activity was not inhibited by treatment with EDTA and Ca^2+ ,Mg^2+ . This lectin had the maximum hemagglutinating activity at pH 4.4 - 7.5, with activity at pH 4.0 - 10.14. The lectin still showed aggllutinating activity after being treated with 90℃ for 30 minutes, indicating that it had a high heat resistance.