The submitted paper evaluates the potential impact of the expected climate change on the climatic water balance of particular vegetation stages of the West Carpathians in Slovakia. The climatic water balance (CWB) is understood as the difference between the amount of precipitation (P) and the potential evapotranspiration (PE), hence CWB=P-PE. The graphical evaluation of the CWB is done by using the modified climadiagrams (comparing the average monthly potential evapotranspiration with precipitations) for the following Carpathian vegetation stages: 1 st Oak, (Quercus), 2 nd Beech-oak (Fagus-Quercus), 3 rd Oak-beech (Quercus-Fagus), 4 th Beech (Fagus), 5 th Fir-beech (Abies-Fagus), 6 th Spruce-fir-beech (Picea-Abies-Fagus), 7 th Spruce (Picea), 8 th Mountain pine (Mughetum), 9 th Alpine. The vegetation stages present the climax potential plant associations as they result from the change of the climate conditions of particular ecosystems according to the changing altitude within the west Carpathians. The analysis of impacts concerning the future climate change (till the 2075 year) according to the scenarios of CCCM points out the high increase of the air temperature degreases of both the precipitation and relative humidity. The increase of potential evapotranspiration will follow the change of water balance within the whole area. In the lower vegetation stages (1 st-3 rd) the water deficit will approach about 200-400 mm during the main vegetation period. The favourable conditions for the expansion of xerophytes and warm temperate dry forest (steppe) plant species will occure. The middle vegetation stages (4 th-5 th) will become more arid (at the assumed water deficit about 50-150 mm). The bioclimatic conditions will be more suitable for the broadleaved tree species (Beech, Maple, and Ash tree) the withdrawal of spruce is assumed. The climatic water balance of the supramontane - alpine (6 th-9 th) vegetation stages will not get worse significantly (the water surplus will approach 150-550 mm during the main vegetation period). The higher air temperature and the sufficient amounts of precipitation can increase the wood production of the tree species growing there. The next negative factors (windstorms, hard rime and others meteorological extremes, harmful insects, fungi patogens, acid pollutants, photooxidants etc.), however, can change the assumed development.