The macroreticular copolymer of a-methyl methaerylatedivinylbenzene with high strength was prepared under various conditions．It was found that the extent of hydrolytic reactions was influenced by the reaction conditions，such as the swelling agents，hydrolytic agents，reaction temperatures，reac-tion time and structure of the copolymers etc．A weakly acidic cation exchange resin of exchange capacity 9 meq／g was obtained bythe hydrolysis of a copolymer of a-methyl methaerylate-divinyl

benzene swollen in 10—100％ of furfuryl alcohol with a hot 60％ sodium hydroxide solution at 150℃ for 4— 10 hours．The copolymer was made by the suspension polymerization of 87.5—-79.2％ of methyl methaerylate and 6—10％ of divinylbenzene (48％ pnrity) with 40—60％ (based on monomers) of # 200 petrol as porogenic agent The percentage of hydrolysis of the copolymer was 90—95％．The cation exchange resin thus prepaxed possessed good me-chanical property and its principal properties is closed to that of the Amberlite IRC-50 made by Rohm and Haas company of the United States．Weakly acidic cation exchange resin was prepared by the hydrolytic reaction of the MMA-DVB nmeroreticular copolymer．The extent of hydrolysis of the ester was 90一95％ and was influeneed by the reaction condittons．The capacity of the resin was ab-out 9 meq/g．The mechanieal strength of the beads is good．The principal properties of the resin are closed to that of the Amberlite IRC-50 made by Rohm and Haas com-pany of the United Staites．