Species composition, abundance and variations of dominance structure of communities of spiders Inhabiting tree canopies have been studied in forest stands of different ages situated in pine forest sites belonging to two regional associations: the subcontinental pine forest (Puszcza Białowieska, Puszcza Biała) and the suboceanic pine forest (Bory Tucholskie). The study has revealed that the greatest differences in both species composition and abundance of spider communities are associated with the age of the forest stand. The following species were most frequent and abundant in the tree canopy spider communities studied: Atea Sturmi, Euryclubiona subsultans, Theridion tinctum, Hellophanus dubius.