Total of 92 spider species were found in the peat bog Na loučkách (Krušné hory Mts., distr. Chomutov). Findings of 19 species are considered as significant: Robertus scoticus, Anguliphantes tripartitus, Aphileta misera, Centromerus pabulator, Drepanotylus uncatus, Gonatium rubens, Helophora insignis, Hilaira excisa, Kaestneria pullata, Maro lepidus, Oryphantes angulatus, Palliduphantes ericaeus, Poeciloneta variegata, Semljicola faustus, Walckenaeria alticeps, Pardosa sphagnicola, Pirata uliginosus, Iberina difficilis, Talavera parvistyla. Species Maro lepidus, Talavera parvistyla, Palliduphantes ericaeus, Semljicola faustus are highly endangered. Palliduphantes ericaeus is reported from the Czech Republic for the first time.