Roseroot (Rhodiola rosea L.) is an adaptogenic plant, widely used in the traditional medicine of Scandinavia, Russia, China and Mongolia. The aim of the study was to determine the biometric and phytochemical co-variability of this species under field cultivation in western Poland (Plewiska near Poznań). The plant material originated from four-year-old cultivation established twice by rhizome division in autumn 2007 and 2008. In the study, 46 individuals (23 plants in 2011 and in 2012) were used. The biometric analysis included measurements of the basic characteristics of plants related to the size (luxuriance) of clumps, shoots, leaves and rhizomes with roots (raw material). The amounts of total polyphenols (expressed as gallic acid), tannins (expressed as pyrogallol) and flavonoids (expressed as quercetin) were determined spectrophotometrically. The obtained results showed high variation of Rh. rosea, especially in the level of flavonoids (0.01-0.20% DM) and in the weight of raw material (113-1156 g FM/plant). There were observed correlations between the phytochemical (flavonoid and total phenolic content) and biometric (water content, leaf number, shoot and clump size) features.