Abstract: The changes of breath rares during the mycelial growth of three basidiomycetes(Ganoderma lucidum ，Hericium erinaceus,Flammulina velutipes)at the mycelial stage were studied．The results show that the mycelial breath rates of three basidiomycetes a11 increase with mycelial growth，but the value of each species is different．The mycelial breath rate is stable during the same growth period． Each curve of mycelial mean growth rate of the three basidiomycetes shows only one peak．The maximum of breath rate comes later than that of the mycelial growth rate.