An aminated complex-type oligosaccharide derivative, for example, of the formula (1) wherein R.sup.1 is H--(CO)--CH.sub.2X, --NH--(CO)--(CH.sub.2).sub.b--CH.sub.2X, isothiocyanate group, --NH--(CO).sub.a--(CH.sub.2).sub.b--CO.sub.2H or --NH--(CO).sub.a--(CH.sub.2).sub.b--CHO, X being a halogen atom, a being 0 or 1, b being an integer of 1 to 4, R.sup.2 and R.sup.3 are a hydrogen atom or a group of the formulae (2) to (5) and may be the same or different, except for the case where both R.sup.2 and R.sup.3 are hydrogen or the formula (5), and the case where one of R.sup.2 and R.sup.3 is a hydrogen atom, with the formula (5) serving as the other thereof.