The aim of the studies carried out in the natural oak-hornbeam forest Tilio-Carpinetum typicum and in the degenerated form in the stage of pinetization Pinus-Lamniastrum, was to obtain and compare qualitative-quantitative structures of soil fungi communities in two different oak-hornbeam forests. This degenerated form of oak-hornbeam forest is the result of removing the natural tree population (typical oak-hornbeam forest) and re-afforesting the resultant vacant area with pines. The study plots were located in such a way that the variations of soil fungi communities were affected only by seasonal changes in the vegetation of the degenerated oak-hornbeam forest Pinus-Lamniastrum. The soils in both study plots are typical forest grey-brown podzolic soils (Luvisols). The results of mycological studies indicate significant differences between soil fungi communities in both oak-hornbeam forests, although similarities especially in species composition of 15 of the most abundant fungi species were also found. The differences are the result of changes in the floral composition of degenerated oak-hornbeam forest. In the past, when typical oak-hornbeam forest covered whole studied areas, the soil fungi communities were probably almost the same in both plots. The first change could have happened after the removal of the trees; the second, after the re-afforestation of the resulting vacant area with pines. The re-appearance of Tilio-Carpinetum typicum in its once occupied habitat causes changes in the soil fungi community in the degenerated oak-hornbeam forest.