Himalayas covers about five countries named as: India, China, Nepal, Bhutan and Pakistan. Mount Everest is the highest peak located in the Himalaya (27°59′N 86°55′E). Himalayan range is bordered on the north-west by Karakoram and Hindu Kush ranges, TibetanPlateau and Indo-Gangetic Plain. Some rivers like the Indus, the Ganges and the Tsangpo-Brahmaputra emerged from the vicinity of the Himalayas. There are different and unique type of species found in the flora and fauna of Himalayan region. Some of these species are endemic and critically endangered. Snow leopard is the main predator found at high altitudes but fall in endangered category. There are many biodiversity hotspots, 353 new species that includes 242 plants, 16 amphibians, 16 reptiles, 14 fishes, 2 birds, 2 mammals and more than 61 invertebrates have been found in the eastern Himalaya in the year between 1998–2008.In Sikkim, the climate varies from sub-tropical in the south to tundra in the north and the average annual temperature in most of the area of Sikkim is about 18 °C. For the protection of the biodiversity in Sikkim the government made many protected areas such as Khangchendzonga National Park, Maenam wildlife sanctuary, Shingba Rhododendron sanctuary etc. The present study is based on the vulnerability of endemic species found in the Sikkim area covers the Himalayan region due to climate change. Sikkim contains different types of plant and animal species which are of great economic importance. The livelihood of people was mostly dependent upon it. There is total 48 plant species and 20 animal species present in the flora and fauna of Sikkim are endemic due to deforestation, illegal poaching, global warming and some climate factors etc. Sikkim had lost 123 ha of its natural forest which is equal to 66.8 kt of CO2 emissions. There is an urgent need of conservation of the biodiversity through various methods such as creation of protected areas, captive breeding and reintroduction or by increasing awareness among public for sustainable use of species.