Phenol and 4-substituted phenols were polymerized by H2O2 as an oxidant and hemin as a catalyst in organic/buffer mixed solvents. The chemical structures of the polymers were similar to those synthesized by the catalysis with horseradish peroxidase. Among the organic solvents used, pyridine gave the highest yield of polymer. Also, the manner of addition of H2O2 solution affected the polymer yield.