EN
The aim of the article was to verify the hypothesis that the provenance, which manifests itself at the antiquarian auctions in the form of bookplates, supralibros, stamps, written records, etc. is an important element of attracting attention of book collectors, affects their purchasing decisions, and is measurable. To verify the validity of this assumption, an analysis was made of the assortment of one of the largest Polish scientific antiquarian bookstores - Cracow's Rara Avis Antiquarian Bookshop. Empirical base formed a non-random trial research which considered 30557 descriptions, that is approx. 41% of the whole assortment. The results of analyses confirmed the established hypothesis, because the proportion of objects marked with provenance was high (averagely 31.2%) and stayed on the same level throughout the studied period (21,1-44,2%.). In the course of the analysis it was established that the test object type most often comes from private collections (82.4%), and the dominant categories of marks are: seals (36.7%), the signatures of ownership other than authorial (19.6%), notes of ownership (10.5%), ex-librises (9.8%) and authors dedications (8.7%); but far fewer works contain the signatures of the authors (4.0%), dedications different than authorial (3.7%); the rarest ones are supralibros (only 1.7%).