Structure of psocid taxocenoses (Psocoptera) were intensively studied in forest ecosystems of the Western Carpathian Mts. and Polonic biogeographical subprovincy during 1997–2001 in the Czech Republic. Vegetation tiers (= altitudinal vegetation zones) were used as a study frame. Only a part of material, i.e. individuals that was found in the forest ecosystems of Querci-fageta s. lat. communities (= the 3rd oak-beech vegetation tier) was evaluated for purpose of this work. This vegetation tier is widespread in large part of the Opavská pahorkatina hills, in large parts of Podbeskydská pahorktina hills, in the Bílé Karpaty hills and in the foothills of the Vsetínské vrchy hills. 1201 adults comprising 29 species were found in total in the 3rd vegetation tier. As eudominant species, the following ones were found: Peripsocus subfasciatus, Caecilius flavius and Stenopsocus lachlani, as dominant species, the following ones were found: Philotarsus parviceps and Caecilius piceus. In natural geobiocenoses with the level of naturalness of 1 or 2, the following species were found: as eudominant species: Caecilius flavidus, Peripsocus phaeopterus, as dominant species, the following ones were found: Caecilius piceus, Peripsocus subfasciatus, Philotarsus parviceps and Elipsocus moebiusi. Taxocenoses of psocids were evaluated by Detrended Correspondence Analysis (DCA) and Divisive Cluster Analysis (DvClA). This material was compared to another material gained from various vegetation tiers in the Western Carpathians Mts. The characteristic species composition of psocids in the 3rd vegetation tier was as follows – Elipsocus moebiusi – E. hyalinus – Philotarsus parviceps – Ectopsocus meridionalis – Caecilius flavidus.