The aim of the present study is to monitor the forest vegetation’s condition and detect changes occurred in the territorial disturbance of the forest cover in the area of Natural Park "Blue Stones", located in Bulgaria near to Sliven town, by the use of combinative approach of Remote Sensing’s methods and generation of different vegetation indices (NDVI, NDGI). The predominantly forest species of the plantations in the park are European Beech (Fagus sylvatica L.) and Eastern Moesian Beech (Fagus orientalis Lipsky) - also known as Oriental Beech. Tasseled Cap Orthogonal Transformation is applied to the selected satellite images, resulting in three TCT components - "brightness", "wetness" and "greenness". In the present research, on the basis of the "greenness" component from different temporal points (satellite scenes), Normalized Differential Greenness Index has been calculated which is giving more accurate and precise data on the current state of the forest vegetation for a given time period (2016-2021). A comparative analysis of the processed data obtained by the applied different methods and vegetation indices has been made. A selection the higher qualitative and more precise results was made in order to make analysis and assessment of the condition of forest vegetation on the territory of the Natural Park.