In this diploma thesis we will focus on alpine natural forests. The investigated area is located in the Poľana Protected Landscape Area. The data we used for the analysis were measured on the TVP network, which is located in stands 526 and 527. In the introduction to the present work, the description of Norway spruce, its distribution in Slovakia, ecology, variability and significance are generally discussed. In the next part, we focused on a more detailed description of the Highlands forests, specifically the 7th spruce vegetation stage. And in the last theoretical part we focused on the description of natural forests (rainforests) and the natural regeneration of spruce in these forests. The aim of the presented work was to analyze the structure of adolescents up to 8 cm in terms of number, thickness and height structure. We obtained the used data by direct measurement on TVP. We entered the data into the Excell program where we calculated dendrometric quantities and then created graphs. From the data set, we sorted individuals that fell into the category of adolescents and we used graphs to show the relationship between their thickness and crown parameters.