The input of a proton load from the contaminated air has been followed in the area of the beech Ecological Experimental Stationary (EES) of Kremnicke vrchy Mts, on the Research Monitoring Plots (RMP) K zimnej vode in the Beskydy Mts and Certova svadba in Low Tatras Mts throughout a period of three years. It offers a picture of a different contamination degree of the atmosphere on the given plots (Table 1). Mean values in the area of the beech EES Kremnicke vrchy Mts were only 8.9 mmol H+.day-1.m-2 in the RMP K zimnej rode 29.0 mmol H+.day-1.m-2 and in the RMP Certova svadba 25.5 mmol H+.day-1.m-2. The comparison of values of the proton load on the bare spot and in the stand as well as the comparison of summer and winter seasons is given in Table 1 and Fig. 1. The proton load dependence of altitude presents Table 3. The achieved results suggest that forest positively influences reduction of the proton load on the given plots.