A new cross-linked resin was prepared by an inverse emulsion method under the protection of amino group. The resin reacted with glycidyl trimethylammonium chloride to form the quaternary ammonium ion resin, whose chloride was exchanged with potassium borohydride to get the borohydride exchange resin (CBER). CBER was used as a new polymer-supported reducing agent for the reduction of carbonyl compounds to corresponding alcohols, and exhibited a relatively high chemoselectivity and possessed the advantage of easy work-up. (C) 2002 Elsevier Science B.V. All rights reserved.