A novel type of maleimide-based monomers, N-[o-(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)phenyl]maleimide (DMOPMI), (+/-)-N-[o-(4-ethyl-4,5-dihydro-1,3-oxazol -2-yl)phenyl]maleimide ((+/-)-EOPMI), and (R)-N-[o-(4-ethyl-4,5-dihydro-1,3-oxazol-2-yl)phenyl]maleimide ((R)-EOPMI), were synthesized for the first time. Their polymerization behavior was studied briefly by both radical and anionic initiating mechanisms. The results indicated that the addition polymerization takes place mainly in the vinylene group without appreciable side reactions. The polymerization in low polar media tended to increase molecular weights or optical activity of the obtained polymers.