Aim. To determine the quality of diterpene glycoside powders, produced in Ukraine using the stevia leaves of plants of domestic and foreign origin. Methods. Differential scanning calorimetry and thermographic analy- sis. Results. It was demonstrated that the increase in the production of powders of diterpene glycosides in the world results in stepping up the requirements to the selection material of stevia and the quality of powders, obtained from its leaves as a fi nal product. The quality of diterpene glycoside powders, produced in Ukraine us- ing the stevia leaves of plants of domestic and foreign origin, was investigated. Conclusions. It was determined that special attention in the analysis of the powder samples of diterpene glycosides should be paid to the sample preparation: increased humidity of the sample promotes a weakening of carbohydrate bonds and rapid decline in their quality. Differential scanning calorimetry allows determining the content of additives, the degree of moisture saturation, and may further be used in the screening of selection samples and forecasting the shelf life of powders of diterpene glycosides.