The objective of the paper was to assess the basic chemical composition of Asian pear fruits with reference to the European pear fruits, as well as to evaluate changes occurring while storing them. Fruits of three cultivars of the Asian pears: Shinseiki, Hosui, and Chojuro, as well as fruits of the European Konferencja pear cultivar were analyzed. The fruits under investigation originated from the experimental orchard owned by the Department of Pomology and Basic Natural Science in Horticulture – SGGW. The investigation was conducted in the year 2003. Immediately upon the harvest, the fruits were analyzed (they were at a stage of the harvest maturity), and, again, after the 1, 2, and 3 months of having been stored in a common refrigerator. Under the scope of this analysis, the following parameters were determined: dry matter, soluble solids, titration acidity, total saccharides, and total phenolics. The chemical composition of the Asian pears differed from the chemical composition of the European Konferencja pear cultivar in the dry matter content, extract, and acidity. When the period of storing pears was prolonged, the content of dry matter and extract seemingly increased, probably owing to the transpiration processes occurring; however, the acidity level decreased.. The content of polyphenols, responsible for antioxidant properties of the Asian and European pear fruits investigated, depended on the type of pear cultivar. The highest content of polyphenols was stated in the Chojuro fruits whereas the lowest content – in the Shinseiki cultivar. During the storage period, it was stated that at the beginning of storing, the content of polyphenols in pears increased; the maximal content of polyphenols was determined in the Konferencja fruits after the first month of storing them, and in the Asian pears: after the two months. As for the ensuing analyses performed on the dates as scheduled, it was stated that the content of these particular fruit compounds, appearing beneficial for health, decreased in all the fruits analysed.