The results of production and statical stability of the beech root system determined in 10 localities on an optimum area are presented. 170 root systems from windfall and 9 from standing trees were measured and evaluated. The length and width of a root system, rhizotaxis and diameter in different soil types, rooting, sanitation state, physical and mechanical soil qualities were investigated. The results document that the priority condition for growth and distribution of roots is the availability of groundwater. The root depth did not exceed 130 cm and the root system width reached 550 cm as a maximum. The roots with diameter above 10 cm were the factor which had influenced mostly the stability. The total beech root biomass in dry weight was 44,175 kg.ha-1 in soils rich in minerals and 47,590 kg.ha-1 in poor soils.