Abstract: Spore laccase from Bacillus amyloliquefaciens LC03 has good stability. In this work, spore suspension with laccase activity was prepared and tested for its ability in decolorization of four synthetic dyes,including remazol brilliant blue R(RBBR), reactive black 5, indigo carmine and crystal violet. Laccase mediators were screened to improve the decolorization process. The effects of enzyme and mediator concentration on simulated dye effluent decolorization were also investigated. The results showed that no decolorization of RBBR, reactive black 5 and indigo carmine occurred in the absence of mediator, while more than 60.00% decolorization of the three dyes were obtained when acetosyringone (ACE) was present. The spore laccasemediator system could efficiently decolorize the simulated dye effluent with 88.64 U/L of spore laccase and 0.5 mmol/L of ACE at pH 9.0. More than 80.00% of simulated dye effluent was decolorized after 2 hours, indicating potential application of this spore laccase in dye wastewater treatment.