For the synthesis of a new biologically functional polymer from a natural resource by an environment-friendly method, the laccase-catalyzed polymerization of a lignin-based macromonomer, lignocatechol, was carried out for the first time in ethanolphosphate buffer solvent system to give crosslinked polymers in good yields. Lignocatechol was prepared by the phase separation system of lignin and catechol in aqueous sulfuric acid. The copolymerization was also performed with urushiol to afford the corresponding copolymers in high yields. The polymerization mechanism was estimated by the IR and pyrolysis GC-JAS measurements, suggesting that the polymerization proceeded mainly at the catechol ring through a quinone radical intermediate. The thermal properties were measured by the DSC, TG, and TMA analyses, indicating that the polymers had high thermal stabilities because of the crosslinked structures. In addition, it was found that the resulting polymers bad the affinity of bovine serum albumin (BSA) and glucoamylase. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 824-832, 2009