Norbornene derivatives, including four novel structure compounds, bearing sterically hindered phenol (SHP) were prepared as functional monomers (1-3). The ring-opening metathesis polymerization (ROMP) of these functional monomers was carried out with typical ruthenium catalyst [bis(tricyclohexylphosphine)benzylidene ruthenium(IV) dichloride] that was so called as first-generation Grubbs catalyst to prepare hindered phenol functionalized polymers possessing radical scavenging function. The resulting polymers were characterized by means of gel permeation chromatography (GPC), H-1 and C-13 NMR, and differential scanning calorimetry (DSC). The radical scavenging ability of polymer was evaluated by determining RSA using the a,alpha-alpha diphenyl-beta-picrylhydrazyl (DPPH) free radical. The results show that the resulting polymers have different radical scavenging ability with the difference in structure of side chain. Polymers bearing 3,5-di-tert-butyl-4-hydroxyphenyl-propionate (DBHP) side chain have a higher radical scavenging ability than the polymers bearing 3,5-di-tert-butyl-4-hydroxy-benzoate (DBHB) as side chain. The molecular weight of polymers is dependent on the ratio of molar concentration of monomer to catalyst ([M]/[C]); monomers bearing DBHP group have a higher activity for ROMP than the monomers bearing DBHB group comparatively. (c) 2007 Elsevier Ltd. All rights reserved.