This master thesis focuses on damage caused by the ruminant game on young forest vegetation in a selected area, in connection with sustaining its natural restoration. The first part of the master thesis deals with the characteristics of the natural conditions of the chosen area and the protected landscape area of Štiavnica Mountains. In the next chapter we analyze the biology of deer and roe deer, its food demands and preferences of the forest-tree species as their source of food as well as their ethology. Third chapter is dedicated to the issue of damage caused by deer and roe deer on the young forest vegetation in the stage of its regeneration process. Fourth part consist of procedure and analysis of the inventory of the damage of the natural food sources in selected areas in the last three years, focusing on deer and roe deer, and also on the evaluation of its influence on the regeneration of the forest vegetation and analysis of the possible causes of the damage caused in selected areas. The last chapter introduces the rationalization measures within the game management as well as the forest enterprises in connection to sustaining the minimal negative impact of the ruminant game on the forest ecosystems and the suggestions for the possible preventive measures.