Abstract: Laccase from Coriolus versicolor was immobilized by adsorbing first on activated carbon, and then entrapping into calcium alginate gels. 2,4-Dichlorophenol in wastewater was dechlorinated by the immobilized laccase in a columnar reactor. The optimal temperature and pH for the reaction were 40℃ and 4.5, respectively. Compared with free laccase, the immobilized laccase had better thermostability, and also had a broader active range of pH and temperature. The decholorination efficiency of laccase on 2,4-dichlorophenol (1 mmol•L^-1) was all above 99.5% with 0.5 mmol•L^-1 chloride ions released into the water during 8 repeated batch reactions. The results showed good prospect of application in the biochemical treatment of polluted wastewater.