The main target of this diploma thesis was to determine the number of spiders in the cavities and on the bark of fruit trees in the wider area of the village Želetice. The re-search was conducted on Prunus avium, where I chose 37 trees in two localities. Spiders have gathered in cardboard and newspaper traps within a year, I have been choosing traps every month. In total 888 traps were placed and 254 spiders were captured. Juve-nile individuals were 310 and adult 44, most represented by the family Philodromidae with 45.3% of all individuals. Spiders were divided into 11 families and 20 species, the most abundant species was the Nuctenea umbratica. Most spiders were in November, 52 individuals. Proportion between the placement of the trap was 56 % of spiders on the bark and 44 % of spiders in the cavity.