Abstract: We determined the levels of similarity between the complexes of plants, spiders, allbeetles and carabid beetles inhabiting different biotopes of an agroecosystem: forest belts, fieldmargins and the arable field (at 10, 200 and 400m from the edge). Geobotanical analysis,entomological netting and pitfall traps were used. Boundaries between plant communities wereclearly expressed whereas arthropod communities were not confined usually to a certain biotope.The catches of all arthropods by pitfall traps in different biotopes were more similar than thecatches by entomological net. Differences of all communities within the field were minimal butthe influence of adjoining biotopes was obvious. The difference of spider complexes in differentbiotopes was greater than this difference between beetles complexes. All differences increasedaccording to the distance from one collecting place to another.