Three extracts of Calendulae officinalis flos (Asteraceae): heptane, ethyl acetate and methanol were introduced to a human skin fibroblast (HSF) cells culture and a culture of human breast cancer cells (T47D), cell culture collection ECACC number 85102201. The ethyl acetate but not the heptane and methanol extracts in concentrations above 25 microg/mL, can stimulate cell proliferation and cellular metabolism by increase of mitochondrial dehydrogenase activity. However, concentrations exceeding 75 microg/mL are toxic for cells. The second part of the study concerned elaborating of optimal chromatographic systems for quantitative analysis of these extracts by the use of HPTLC with densitometry. Oleanolic acid, beta-amyrin, beta-amyrin acetate, rutin, narcissin, 3-glucoside of isorhamnetin, quercetin, isoquercitrin, vanillic acid, caffeic acid, chlorogenic acid, protokatechuic acid, p-coumaric acid and syringic acid were all identified.