Two novel dextran surfactants, N-n-hexyldextran aldonamide (diblock AB type) and N,N’hexamethylenebis(dextran aldonamide) (triblock ABA type), which were composed of hydrophilic dextran oligosaccharide (M(w) = 1600) and hydrophobic hexamethylene, were synthesized and characterized by GPC, FTIR, and H-1-NMR. The dextran surfactants were prepared by the selective oxidation and lactonization of the reducing end groups of dextran oligosaccharide, followed by the aminolysis with hexylamine or 1,6-hexanediamine. The intermediate lactones reacted selectively with amines to form the amide linkages, obviating the need for protecting the hydroxyl groups in the dextran. To optimize the reaction conditions and purification methods, model compounds were synthesized from D-maltose monohydrate. An ion-exchange chromatography method was developed to purify the dextran surfactants, based on the fact that the dextran surfactants are nonionic while the impurities are ionic. In addition to linear diblock and triblock polysaccharide surfactants with different block chain lengths, the synthetic approach described in this report also provides a practicable route for the preparation of starlike and comblike polysaccharide surfactants.