New copolymers were prepared by radical polymerization starting from N-1-adamantylmaleimide (AMI) and styrene (ST). The copolymerization of AMI with ST proceeded easily to give medium molecular weight of copolymers (<(M)over bar n> > 10(4)) in high yield. The poly(AMI-co-ST)s had high Tg (205-236 degrees C) and good thermal stability. Moreover, the poly(AMT-co-ST)s exhibited activity against the staphlococcus aureus ATCC 25923. The monomer reactivity ratios(r(1),r(2)) in the copolymerizations of AMT with ST, and Alfrey-Price Q, e values for AMI were determined.