An anhydride moiety, which leads to carboxylic groups on processing is an interesting starting material as metal-chelating agent. Maleic anhydride is found to pose certain problems in preparing a copolymer. Heat of polymerization poses certain problems during copolymerization of styrene-divinylbenzene-maleic anhydride, and also divinylbenzene and maleic anhydride. Two-step addition of solvent is adopted to control the heat of polymerization during the preparation of above copolymers in bulk form. In case of bead polymerization water cannot be used as suspension medium. In the preparation of copolymer beads, even the presence of small amount of water converts anhydride to carboxylic group, which prevents effective polymerization. Attempts have been made to prepare above copolymers both in bulk and bead form to get carboxylic resin. The resin is characterised.