We observed hydrogen ion deposition and proton load input into beech forest ecosystems and its long-term tendency on the research plots at the Beech ecological experimental station (BEES) Kremnické vrchy Mts. The research period covered 1993-2000. The highest annual precipitation at this locality was measured in 1994, reaching the mean (from all the plots) value of 834 mm. In the other years the amounts moved from 428 to 705 mm. The corresponding values of the mean annual deposition of H+-ion were 0.179 kg H+ ha-1 year-1 observed in 1994, and considerably lower ones in the other years: 0.018 - 0.144 kg H+ ha-1 year-1. The mean annual proton load value was the lowest (4.9 mmol H+ day-1 m-2) in the driest year of the research period (1993). In the other years this value was higher, moving from 9 to 13.5 mmol H+ day-1 m-2. For each plot of the BEES we calculated the mean values of annual precipitation, hydrogen ion deposition and proton load. Then we compared the obtained values between the individual plots.