Twenty-six species of ammonia fungi comprising 71 strains were screened for ligninolytic activity using agar plate tests. The tests comprised a wood powder plate test, the Bavendamm reactions, and a Remazol Brilliant blue R (RBBR) decolorization test. The wood powder plate test detected phenol oxidases of Coprinus spp., whereas this method obviously detected no activities from facultative mycorrhizal fungi, such as Hebeloma radicosoides and ectomycorrhiza: H. spoliatum and H. vinosophyllum. With quantitative assays of ligninolytic activity, Coprinus phlyctidosporus, C. echinosporus, Lyophyllum tylicolor, Lepista nuda, L. tarda, Calocybe leucocephala, and Crucispora rhombisperma, which grow on oak-leaf litter, the major phenol-oxidizing enzyme was a laccase. The concentration of urea affected laccase activity; however, urea was not the obligate nitrogen source for the laccase production.