Arachnofauna of the topmost area of the western Giant Mts. was observed in the period 19971999. Species composition and abundance of particular populations have been assessed in spider communities of (1) sites shaded by shrubs or krummholz of dwarf pine and shrubby Norway spruce, and (2) open sites lacking any closed-canopy screening. The results confirm marked difference in species composition and size of population of spider communities in the above named habitats. Spider fauna of microrelief elevations and depressions induced by cryogenic processes (patterned grounds) within the non-shaded sites does not essentially differ between each other.