The bryophyte vegetation of three acidophilous forest communities of four habitats on radiolarian bedrock were investigated in the Bükk Mts. The bryophyte layers of Deschampsio-Fagetum sylvaticae Soó 1962, Genisto pilosae-Quercetum petraeae Zólyomi et al. 1958 and Genisto tinctoriae-Quercetum petraeae Klika 1932 were compared on the basis of the dominance and frequency of 15 bryophyte species in the communities using ordination and cluster analysis methods. The soil pH and the photosynthetically active radiation (PAR) values in the four sampling areas were also compared. The results refer to a strong connection of the bryophyte species composition considering the dominance values and frequency of the species with the community type in different spatial scale. The soil pH values do not differ significantly in the habitats and they refer to a high amount of hidden acidity which is the effect of the radiolarian bedrock type. The PAR values have been statistically analysed and represent the homogeneity or the heterogeneity of the canopy layer and the effect of the exposition. The results show significant difference in the variances of PAR values between Genisto pilosae-Quercetum and the other two community types and the mean PAR value of Deschampsio-Fagetum sylvaticae differ significantly from the mean values of the two Genisto tinctoriae-Quercetum petraeae stands.