The main focus of the diploma thesis is to find out and evaluate the influence of the natural structure of the tree layer on the diversity and species composition of the herb layer in the primeval fir-beech forests present on the crystalline basement in the National Nature Reserves of Šrámková and Šutovská valleys in the Malá Fatra Mountains. The thesis deals with the phytosociological relations analysis as well as with the data analysis. This is done to assess the impact of dendrometrical, structural and disturbance characteristics on the herb synusia. The data has been gained from 26 permanent research areas based in the mentioned nature reserves. We have processed the data using Microsoft® Excel where we performed the individual correlation analyses. We have also used the Canoco program in which we conducted the multidimensional analysis using all of the selected structural and disturbance characteristics. Our results have shown that the characteristics of the stands influence the herbal layer significantly, especially the characteristics expressing the number of individuals and the volume of the biomass. Regarding the disturbing characteristics, the time since the last disturbance and the power of the last disturbance have proven to be the most significant ones.