The primary amino group, the competitive inhibitor of maltase, was used as ligand and the enzyme was purified to homogeneity in a single step. The amino group affiants of ethylene (C2-NH2) and hexamethylene (C6-NH2) diamines were prepared by coupling to cyanogen bromide activated Sepharose CL-4B. The enzyme was quantitatively adsorbed at alkaline pH (pH 8.2), while the elution could be effected only in presence of maltose at acidic pH. The elution of enzyme by maltose was independent of spacer arms (C2 and C6) which suggests specific binding of the enzyme through inhibitor site.