The aim of the thesis is to analyse the thickness increment of European spruce and European larch in selected forest covers transformed to selection forest. In terms of forest and economic growth, analysed parts1631 and 1632c classified according to Zlatníková (1976) as forest types Fagetum abietiono-piceosum and Piceetum abietinum in LHC Liptovská Osada, LC Liptovská Osada – orographic unit of the Starohorské vrchy Mts., Slovakia are analysed. Forest cover consists especially of European spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.). Less common wood species in this area are European beech (Fagus sylvatica L.), European larch (Larix decidua Mill.), Scots pine (Pinus sylvestris L.), sycamore maple (Acer pseudoplatanus L.) and mountain ash (Sorbus aucuparia L.) Therefore, only the core drills of European spruce and European larch were evaluated. Core drills from selected individuals were taken using the Pressler drill by stratified random sampling. Modified specimens were scanned using Epson Expression 10000 XL with the optical resolution of 1200 dpi. Core drills were evaluated using the software Régent Instruments Inc. WinDendro®, while thickness of growth rings of individual core drills with accuracy of 0.001mm were determined. Following the gathered data, the fact that the part 1631 is younger than the forest cover 1632c was observed. In 1631, the lowest analysed age was 40 and the highest one was 147. In 1632c, the analysed age ranged from 23 to 229. All three-forest layers were evaluated. Higher values were observed in the case of younger part (1631) than in part (1632c). Higher values of analysed data were in the case of increments, number of trees, forest supply. Thickness increment of European spruce depends especially on the position in the forest cover.