This master‘s thesis studies problems of chosen active substances in cosmetic emulsions and gels. There is their main characteristics – distribution and properties of cosmetic emulsions and gels, preparation of the active substances, effects on the skin and conditions, which could them influence. In experimental part, preparation of gels and emulsions bases was described which were than enriched by active substances - evening primrose oil, hemp oil, Salvia officinalis extract, Symphytum officinale extract and sea salt. Properties of these cosmetic gels and emulsions bases with the addition of active substances depend on temperature and method of storage, amount of light exposure, method of preparation and another conditions. Action of these factors can cause changes of the stability, thereby the cosmetics effects on the skin can be lost. On the bases of performed rheology measurements (oscillation and flow measurements), pH measurements and sensory analysis were determined, if the properties of examined samples were changed. The measurement was performed in the certain time intervals and the properties were evaluated like at laboratory temperature 23±2 °C, so after exposure to temperature regime 37 °C in thermoregulator. On the basis of performed measurements, there was determined, that gel base with addition of Symphytum officinale extract had the most stability properties.