The authors demonstrate a possible relationship between the concentrations of metals (Cd, Cr, Cu, Fe, Ni, Pb, V, Zn) measured in mosses and the composition of Tardigrade species detected in the same samples. Cushions of Hypnum cupressiforme were collected at 18 sites distributed in the whole of Hungary to estimate the background air pollution, then analyzed by ICP-AES to determine the concentrations of heavy metals. Data reflect the expected correlation; elevated heavy metal contents decrease the number of water bear species and of specimens, and abundance of Tardigrada depends strongly on air pollution. Higher concentrations of cadmium and chromium seem to have particularly damaging and toxic influence on community structure. As the biologically relevant effects of pollution can only be evaluated by carrying out measurements on the organisms themselves, our method applied species of Bryophyte and of Tardigrade, as bioindicators were appeared to be an adequate method to show the effect of air pollution on abundance of water bears.