In the article there are presented changes in concentrations of phenolic compounds caused by applied methods of preservation in fruits of a rowan (Sorbus aucuparia). Samples have been preserved for 150 days with analyses having being done at 30, 90 and 150 days of preservation in 4 °C with the humidity of 67±2%. Preservation was carried out in shut polyethylene and vacuum package. Spectrophotometrically and by titrimetric (volumetric) analysis, there were detected concentrations of following phenolic compounds: monomeric such as flavonoids and polymeric (tannins). Analysis of the data of the studied samples of fruits of Sorbus aucuparia variety Nevezhinskaya (Sorbus aucuparia "Nevezhinskaja") in terms of the total content of flavonoid compounds was 53.126 mg/100g of absolutely dry substances., at the end of the storage period, sample No. 5 using vacuum packaging differed in the content of flavonoids at the level of 4.268 mg/100 g .Chlorogenic acid’s concentration in 100 g of a natural product was examined to be 12.16 mg/100g at the beginning and 8.04 mg/100 g at the end of the preservation. Catechins concentration at the beginning of preservation equaled 29 mg/100g and lowered to 7 mg/100 g absolutely dry substances. The most tannins concentration loss during preservation was measured to be at 90 days of preservation, however there was believed to not to be any connection to the type of package samples were preserved in. On the other hand, total phenolic compounds’ concentration in fruits of Sorbus aucuparia «Nevezhinskaja» diminished more in samples that were preserved in polyethylene, which is due to the presence of molecular oxygen during the preservation (sample #2, #4 at 90 days of preservation).. Preservation in vacuum package allows minimizing phenols’ concentrations decrease for the period of up to 150 days.