|Krkonose Mountains (the Giant Mountains in Czech) as the highest mountains of the Czech Republic belong to the most visited middle-european mountains as they are well facilitated for both summer and winter outdoor recreation. More than 8 million visitors within a year means very serious tourism load on the mountain landscape and ecosystems. Primary impacts (e.g. disturbing plants and animals by trampling and noise, soil erosion or cummulation of rubish) together with secondary impacts of tourism development (a.g. arrising of accomodation capacity, impact on traditional landscape infrastructure by reebuilding of original small mountain chalets, nonsufficient disposal of waste, transport of allochtone organisms) create very cotraversional background for sustainable use of the mountains which are the oldest national park of the Czech Republic. Paper describes these impacts and suggests some forms of conflict solution between tourism development and statutes of the national park.