Abstract: Various components in the extract of digitalis leaves were separated by descending paper chromatography, with formamide as the stationary phase and tetrahydrofuranchloroform-formamide (50: 50: 6.5) or xylene-benzene-methyethylketone (75: 25: 100) saturated with formamide as the mobile phase. After developing, the amounts of the separated cardiac glycosides were determined colorimetrically with xanthydrol reagent. Experimental conditions for the colorimetric method were studied and ascertained. Samples of Digitalis lanata Ehrh. and Digitalis purpurea L. were analyzed by this method.