The importance of ecological factors for medicinal species and their influence on active principles synthesis and the specific uptake of mineral elements from soil are presented. The biological and ecological characters, the medicinal importance, and the protection measurements for some species are given. Ecological knowledge of medicinal plants has a double significance: on the one hand provides information on resorts where medicinal plant species can be found to harvest and use of them, on the other hand provides information on conditions to be met by a possible location of their culture. Lately several medicinal species were introduced into culture in order to ensure the raw materials of vegetable drug industry. Placing them in culture presupposes knowledge of their ecology in natural habitats. By introducing the culture and ensure protection of wild flora species to harvesting abusive, irrational, especially of rare, endangered and protected. Vegetation of Romania is typical temperate continental with moderate temperate influence characteristic of central and Western Europe, specific continental to the Eastern Europe, the presence of the Carpathian Mountains has an impact on natural vegetation, and vegetation in the south has small Mediterranean influence. The therapeutic use of medicinal plants is due to active principles they contain. For the plant body these substances meet have a metabolic role, such as vitamins, enzymes, or the role of defense against biological agents (insects, fungi, even vertebrates) to chemical and physical stress (UV radiation), and in some cases still not precisely known functions of these substances for plants. As a result of research on medicinal plants has been established that the following factors influence ecology them: abiotic - temperature, air and soil humidity, rainfall, solar radiation, prevailing winds, orographic, edaphic , biotic - food and its abundance, intraspecific and interspecific relationships, parasites and predators, anthropogenic - grubbing, pollution of ecosystems, agricultural technology elements, etc..
