According to the criteria of the International Union for Conservation of Nature, the Republic of Serbia is one of the six European and 153 world centers of biological diversity. It is one of the most important regions of biological diversity in Europe because it is characterized by great genetic, species and ecosystem diversity. The great species diversity of this area is shaped by the geographical position and the diversity of ecologically different habitats. The main characteristic of the Serbian flora is the emphasized endemism and the highland areas dwelling. Negative activities in the past have contributed to the reduction in the number of certain plant species as well as their disappearance, which have led to disorder of the whole ecosystem. In situ and ex situ conservation methods are used to preserve the most valuable parts of nature, populations and individual species, and genes. The in situ (on-site) conservation implies the continuous maintenance of populations in an environment where they have naturally developed. The positive effect of the in situ conservation reflects through3 the preservation of the ecosystem as a whole and not only the individual species or genes that are the subject of protection. By establishing the in situ conservation the preservation of other plant and animal species inhabiting the preserved area can be achieved. The in situ is a desirable form of the conservation of the forest genetic resources because it allows the evolutionary processes to take place in the involved populations. The selection and the registration of seed stands is the most commonly used method for the in situ conservation of the forest genetic resources in Serbia. According to the data from the current Register of Seed Facilities published by the Forest Administration, the department of the Ministry of Agriculture and Environmental Protection of the Republic of Serbia, on the total area of 1,842.89 ha in Serbia were separated 126 seed stands, of which 44 stands of coniferous species, 81 stands of herbaceous species and one mixed seed stand. Protected natural assets represent a significant form of in situ conservation of the forest genetic resources because they contain large areas of forest complexes. Currently, the protected areas cover 575,310 ha, or 6.51% of the territory of Serbia. Under protection are 461 areas (November 2015): 5 national parks, 17 nature parks, 20 landscapes of extraordinary characteristics, 68 special nature reserves, 3 protected habitats, 310 monuments of nature, and 38 areas of cultural and historical significance. The ex situ (off-site) conservation of the forest genetic resources implies the maintenance of populations and individuals of different species of trees outside their natural habitat. The most common ways of the ex situ conservation in Serbia are seed plantations, provenance tests, clonal archives, living archives and genetic collections.