A particular group of saprotrophic and ectomycorrhizal fungi produced reproductive structures successively on the forest floor after treatment with some nitrogenous compounds (N compounds) such as urea and aqua ammonia. These fungi were also observed after the decomposition of dead bodies or faeces of animals. Their growth in pure culture was examined in liquid media containing ten different N sources (four inorganic and six organic). The saprotrophic Amblyosporium botrytis, Tephrocybe tesquorum, Coprinus echinosporus and C. phlyctidosporus grew well on ammonium, some amino acids (asparagine, glycine), urea and bovine serum albumin, although A. botrytis did not grow on bovine serum albumin. Coprinus phlyctidosporus grew on nitrate as well as on the above N compounds. Peziza urinophila and Pseudombrophila deerata did not grow on any of the N compounds examined. The ectomycorrhizal Laccaria bicolor, Hebeloma vinosophyllum and Hebeloma sp. showed different patterns of nitrogen utilization: L. bicolor grew well on ammonium, nitrate and urea; Hebeloma spp. grew well on ammonium, nitrate, amino acids, urea and bovine serum albumin. None of the fungi tested grew on ethylenediamine or putrescine. The patterns of growth in relation to the nature of nitrogen supply were discussed in relation to the conditions of soil where these fungi occur.