The significance of medicinal and aromatic plant selection has risen in recent years due to increasing requirements on quality, safety, and efficiency of herbal products. Only selected varieties could guaranty the homogeneity of raw material. The chemical diversity of spontaneous populations is one of the main directions of investigations on medicinal and aromatic plants at the Institute of Botany. The target species under research are following: Origanum vulgare, Thymus spp., Hypericum spp., Achillea millefolium, and Helichrysum arenarium. The analysis of trade figures pointed out that the imported raw material mainly supplies the demands of pharmaceutical industry in Lithuania. The cultivated production covers only 4-6% of the demand for raw material. Wild plant material represents about 29% of total volume used in pharmaceutics. The trade in wild plant species and their resources is regulated by the legislations. In situ and ex situ conservation methods are used to avoid potential danger and existing threats to genetic diversity of medicinal plant species.