More than 40 isolates containing six species of Armillaria from the collections have been analyzed (A. borealis, A. cepistipes, A. gallica, A. mellea, A. ostoyae and A. tabescens) using the PCR of the internal transcribed spacer (ITS). The amplificates were further analysed by RFLP (Alu I, Hinf I and Mbo I) and electrophoreticaly separated both on 3% agarose gel and by IEC- HPLC on TSKgel DEAE-NPR column (Supelco). Digestion with Hinf I allowed discrimination of all six species.