Phenolic compounds were tested by adding to growing cultures of the lignin-degrading basidiomycete, Coriolus versicolor CV3 for growth and laccase (benzenediol : oxygen oxidoreductase, EC 1.10.3.2) formation. Addition of various compounds at the concentration of 4×10^(-4) M stimulated the extraccllular lactase, whereas the mycelial growth was repressed. Enzyme induction was marked by o-toluidine (2.3-fold), 2,5-xylidine (3.1-fold) and p-cresoi (2.5-fold), however the influence of substitutes and/or position on those phenolic rings was not clear. An enzyme component which have apparent molecular mass of 68,000 was intensively induced by 2,5-xylidine, and the other component of Mr 46,000 was not affected: these results appeared to be different from the report by Dollag and Leonowicz(1984), because their results indicated that only low molecular weight component was inducible and the higher one was noninducible. Protein synthesis inhibitors(actinomycin D and puromycin) were also tested and compared with phenolic compounds.