The effect of different concentrations of 6-benzylaminopurine (BAP) 0.25, 0.5, 1.0 and 2.0 mg L-1 on the growth, amino acid content and lipid fatty acid composition of in vitro shoots of curly (Karelian) birch Betula pendula var. carelica were investigated. The study of the regenerative in vitro activity of curly birch tissues demonstrated that BAP promoted shoot growth and callogenesis depending on the phytohormone concentration, whereas the control featured explicit shoot growth inhibition coupled with rapid formation of roots. BAP (up to 1.0 mg L-1) boosted the content of individual amino acids: glutamine (a more than 10-fold rise from the control) and arginine (a nearly 5-fold rise). Further increase of BAP concentration (2.0 mg L-1) resulted in a decrease in glutamine and arginine nearly to the levels of the control. The most pronounced changes in the fatty acid composition under BAP effect occurred in the glycolipid fraction, which plays an essential role in photosynthesis.