Itaconates containing a 1-adamantyl or a 3,5-dimethyl-1-adamantyl estergroup were prepared and polymerized in the presence of a radical initiator. The polymerization reactivity has been investigated in relation to the structure of ester alkyl groups of the monomer. It has been clarified that the adamantyl-containing polyitaconates show high thermal stability, i.e., high glass transition temperatures