In forest ecosystems, there is an important interaction between hydrological cycle and nutrient contents. Rainfalls not only have an important role for entrance of nutrient contents to forest ecosystem, but also have an important role to transfer elements from canopy to forest floor and soil. This study performed to investigate the effect of throughfall and forest floor leachate on base-cations dynamics in a mixed hyrcanian beech forest in Golestan province. Throughfall and forest floor leachate samples were taken through 6 months (winter and spring 2008). Amount of base-cations (Ca2+, Mg2+, Na+ and K+) were compared by T-Test between rainfalls and throughfall. Results showed that the amount of Ca2+, Mg2+, Na+ and K+ contents in throughfall were higher than rainfall (