Abstract: In order to illuminate the importance of revising the methods for determining laccase activity according to the porperties and purpose in the actual use,the physical and chemical properties of isoenzymes LacA, LacB and LacC from Trametes versicolor and the Lcc1 and Lcc2 from Coriolus versicolor and ARA from bacterium were compared in this paper. The results showed that the enzymatic characteristics changed with the types of the laccases and substrates. When otolidine as the substrate, the optimal temperatures of LacA, LacB, LacC, Lcc1, Lcc2, ARA were 60,60,70,60,55 and 75 ℃, respectively. While the guaiacol as the substrate, the optimal pH values of the six enzymes were 5.0,5.0,4.5,5.0,4.5 and 7.0,respectively. The optimal temperatures of LacA were 55,70,60,20 and 65 ℃ for the ABTS, guaiacol, o-tolidine, syringaldazine and 2, 6-xylenol as the substrates, respectively. The five fungal laccase enzymes had good thermal stability between 30 ℃ and 60 ℃ and pH stability between 2.5 and 7.0, while the bacterial laccase had strong stability under high temperature and neutral pH. According to the K_m, it could be concluded that the specificity for ABTS was better than the four other substrates. All the results indicated that the enzymatic characteristics of laccases catalysis from different sources under the same substrate were different. Meanwhile, the enzymatic characteristics of same recombinant laccase under different substrates were also large differences.