The thesis is aimed at the issue of tending of the pure and even-aged premature beech stands in the growth phase of thin stick and maturing stemwood. The object of the research is the complex of beech stands in the forests of Ráztočno - II., District Prievidza in Slovakia. The main aim of the work was to analyse the knowledge concerning the effect of crown thinning with a positive selection on the structure of beech stands. Part of the solution is the establishment of two series of 3 permanent research plots (in Slovak: TVP) where, in addition to the control plot (no interventions), the quality thinning of Schädelin with the first thinning grade and Korpeľ's rationalizationing crown thinning with the second thinning grade, was used. The thesis analyses also the structure of selected forest stands, the dynamics of natural processes and the influence of the selected tending method on the remaining beech stand. In the thin stick phase stand on the control plot, the increase in the volume of the timber at the level of 26.08m3.ha-1 was achieved. The increment in the total volume the timber is 16% higher than TVP 1. Compared to TVP 2, the increment in the volume of the timber on the control area is 20% lower. In the maturing stemwood, we can observe an increase in the volume of the timber on the control plot of 17.28m3.ha-1. This increment is 6.5 m3.ha-1 lower (up to 27%) compared to TVP 1. The results from the examined thinning plots confirmed that the beech in its growth optimum, at a younger age and with the thinning intervention of a higher weight, responds with a significantly higher volume increment.