The area of the Park broadly comes under Champion and seth’s classification type. Sub-Group IIB – Northern Mantane Temperate Forests: and Group 12- Himalayan Moist
Temperate Forest : Sub-Alpine Scrub Forest, alpine Scrubs and Pastures. Thus, the flora of the Park can be broadly subdivided into three forest Zones:
1. Temperate Broad-leaved forest (1,829-2,730 mts) dominated by Quercus Lineata, Quercus Lamellosa, Quercus Pachyphylla, Schima Wallichii,Castanopsis species, Acer Campbellii, Engelhardtia, Juglans regia,Michelia cathcartii, Magnoilia Campbellii and Cinnamounm Obtusifolium.
2. Mixed Coniferous Forest (2,730 – 3,650 mts) dominated by fir, Abies densa, Acer species, Spruce,Picea mrindoides and Junipers (Juniperous species) with associates of taller varieties of Rhododendrons and Bamboo(Arundinaira species)
3. Alpine Scrub and Grass (above 3,650 mts) dominated by common shrubs and herbs like Meconopsis species, Primula species, Prostrating Junipers, Iris Gentiana, Anemone and Delhpinium. Besides, there are many medicinal herbs too- like Aconitum species, Picrorhiza, Orchis latifolia, Nardostachys jamtamsi, Rheum emodi and Panax pseudogingseng.
The Khangchendzonga (High Altitude) National Park is a reservoir of diverse habitats- including some rare and endangered species like the Snow Leopard, Himalayan Red Panda(Sikkim’s State Animal),Musk Deer,Nayan or the Great Tibetan Sheep. Bharal or the Blue Sheep, Himalayan Tahr( Shaipii), Common Leopard, Goral, Serow, Barking Deer, Lesser Cats, Wild Dogs, Tibetan Wolf, Mountain Fox, Tibetan Fox, Himalayan Black Bear, Marmots Monkeys and many Rodent species..
The State is rich in bird-life with around 550 species and sub-species – like the flamboyant high- altitude Pheasants which include Monal Pheasants, Tragopan phasants and Blood Pheasants (the State Bird);Tibetan snow Cock; Himalayan Snow Cock, Snow Partridge, Hill Partridge, Lammergyer, Forest Eagle-Owl, Tibetan Horned Eagle-Owl; Eagles;Falcons;Hawks; and Snow & Rock Pigeons. Most of these birds are physically adopted for high mountain climate conditions and come down to lower elevations during winter when the upper reaches are covered with snow.