The present invention provides substance which can specifically interact with sugar chains. Further, the present invention provides a method for separating, concentrating, or purifying sugar chains or a sugar chain-containing substance in a sample, comprising the steps of: a) contacting a sugar chain-trapping carrier comprising a substance which can specifically interact with sugar chains with the sample in a fluid phase under conditions that the sugar chain-trapping carrier can react with the sugar chains or sugar chain-containing substance; b) isolating a composite of the sugar chain-trapping carrier and the sugar chains or sugar chain-containing substance from the fluid phase; and c) exposing the composite to the conditions that the interaction between the sugar chain-trapping carrier and the sugar chains or sugar chain-containing substance is at least partially eliminated.