Stara planina represents a real treasure island.

It was declared as Nature Park in 1997. This mountain beauty is an area with extraordinary values from the point of view of plants and animals diversities and their communities, as well as geomorphological, geological, hydrological and hydrogeological characteristics, where traditional way of living and culture is present.The surface area of the Nature Park Stara planina is 142.219,64 ha.

On Stara planina there is 1195 taxons of vascular flora, 51 species of moss, which is on a national level 34% of total fond of flora of Serbia. Tertiary and endemorelict herbal species that are held in gorges can be found here, while glacial relicts and endemic species can be found on higher parts of the mountain.

Endangered plant species are of extraordinary significant value, whether there are few of them or whether their habitats are endangered. There are 147 species of this kind on Stara planina, and 40 plants that are put under protection as natural rare species on the territory of Serbia. Some of them include:  mountain pine, green alder, grayish oak, pheasant's eye, pasque flower, Kosovo peony, Heldreich's maple, forest lily, heart-flowered Marsh-orchid, german iris and others.

Stara planina is covered by a vegetable cover of 52 plant communities, and their order depends on environmental impacts that interfere in various habitats. Richness of vegetation is expressed through variety of bushy, forest, meadow, pasture and peat communities. Altitude vegetation zones can also be distinguished: oak zone, beech zone, spruce zone, subalpine bushy vegetation, vegetation of creeping juniper, blueberry and subalpine spruce and mountain pine zone. Unique asset make peat communities that are located in the zones of beech and conifer forests on Jabučko ravnište, Dojkino vrelo and on the terrain of Arbinje.

Relict semi-dominant forest communities have also developed on Stara planina which contribute in growing plant species of endemic and relict character. Until now strictly natural reserves have been secluded:

- „Draganište" - reserve of spruce forests

- „Golema reka" – beech rainforest

- „Vražja glava" – significant locality in forest complex of Stara planina, where spontaneous growth and progression of plant species can be tracked in the species of its composition, and especially of the mountain maple.

- „Smrče" (Arbinje) – the best preserved and most beautiful spruce forests on Stara planina and in Serbia generally, with typical peat and sphagnum communities.

- „Kopren" – represents the habitat of carnivore plants

In this area, many animal groups that contribute to the nature beauty are represented. Fauna consists of 116 butterfly species (22 newly established, and 6 species of glacial relicts), 18 species of herpetofauna (6 species of amphibians and 12 species of reptiles), while ichthyofauna is represented with 26 species.

The greatest bird diversity in Serbia, ex Yugoslavia and larger part of the Balkans, is right here on Stara planina, where their habitats found around 203 species. Stara planina is included in the register of areas of international importance for birds of Europe - IBA with an area of 44,000 ha. The fauna of mammals is represented by 30 species, particularly leeches, snow voles, lynx and bear.