The aim of the research was to determine the effect of medium on the mycelium growth of L. sulphureus. The subject of the studies were six L. sulphureus strains: LS02, LS206, LS286, LS302, LSCNT1 and LSCBS 388.61. Eight different agar media and six solid media were used in the experiment. Some morphological characteristics of mycelium on agar media were also evaluated. It was found that PDA was the best agar medium for mycelium growth of all tested strains. The strain LS302 was characterized by very high growth rate regardless of the examined agar medium. The tested strains presented changes in mycelium morphology on different agar media. The best mycelium growth was obtained on alder, larch and oak sawdust media, mainly in LSCBS 388.61, LS02 and LS286 strains.