Environmental factors such as temperature and humidity directly affect the growth and fruit bodies of fungi. We studied the diversity of wood decaying fungal species, which have grown on same substrate in forest as well as laboratory environment. Ten specimens of fruit body of wood-decaying fungi and 24 random pieces of coarse wooden debris were collected from the forest of northwest Arkansas. The samples of coarse woody debris were incubated in laboratory-growth chambers for two months to promote the fungal growth. Fourty-two different species of wood-decay fungal isolates were recovered and identified by internal transcribed spacer (ITS) region sequencing. The isolates from the forest belonged to twenty-two different taxa whereas twenty taxonomic groups were reported from the growth compartments. Remarkably, data observed from two sets did not shared any taxon. These results indicated that environmental growth conditions play crucial role on fungal diversity even if grown on same substrates.