The paper is focused on mapping, analyse and evaluation of the landscape structure changes in high-mountain environment within 50 year time period, with a special respect on subalpine and alpine belt of the selected part of the Predne Medodoly valley in the Belianske Tatry Mts, belonging to the Tatra National Park. The territory was strongly influenced by humans till 1954, especially by means of cattle and sheep grazing. The aim was to record changes in the landscape in two time series, starting since the year 1949 and 1998, as well as to evaluate them qualitatively and quantitatively. Another aim was to analyse causes of these changes with the exploration of human and natural factors as well. For this purpose a set of aerial photographs scanning the study area, namely from the year 1949 and 1998, was used and processed by GIS tools. The map outputs were processed digitally in vector format at the large-scale 1:1500.