Abstract: Asn-linked glycoprotein having antitumor activity, with molecular weight of 32-84 kDa, its producing strain, production and use, adsorbs to Con. A. The process for its production comprises culturing a microorganism belonging to genus Aspergillus and isolating from the culture medium Asn-linked glycoprotein having a molecular weight of 32-84 kDa which adsorbs to Con. A, or a mixture thereof. The substance having antitumor activity is effective for treatment of solid tumors, ascites tumors, multiple cytoma and oval tumors and for the suppression of tumors.