Taxonomic relations among three species of some edible fleshy fungi(Lentinus edodes, Pleurotus ostreatus, Flammulina velutipes) in the family Tricholomataceae were examined by using polyacrylamied gel disc electrophoresis. The soluble, crude extract of mycelium grown on potato sucrose broth was subjected to electrophoresis. Similarities in the protein bands for each isolated of one species were compared with those for others. In the banding patterns there was a closer relationship between isolates within one species than among isolates of different species. However, the isozyme patterns obtained from each isolate of Peurotus ostreatus (esterase, peroxidase, tyrosinase) were appeared to represent the degree of geographical variability within one species.