Oxidative polymerization of 5-cyano-2-methoxyphenol was achieved with high C–O coupling selectivity by an enzyme model-catalyst as the first example of a cyano-substituted phenol. The electron-withdrawing/donating interaction of the substituents would lead to the high reactivity and selectivity. Surprisingly, the resulting polymer showed a very narrow molecular weight distribution. The polymer consisted of a linear unit with small amounts of branched and bent units, in which C = O structure was slightly detected but could be reduced by lowering the reaction temperature.