It is traditionally accepted that the Lepchas are the autochthonous tribe of Sikkim. After them came the Bhutias from Tibet, followed by the Nepalese from Nepal and finally the Indian business community from elsewhere in India. It is necessary that before one goes into the ethnic composition of Sikkim, it needs to be said that Sikkimese irrespective of the tribe, class or community they belong to, are essentially simple folks. Sikkimese people truly exemplify the ideal hilly tribes wherein they remain untouched by consumerism and prove by showing how different communities can co-exist in peace and harmony.
Sikkimese people are broadly classified into the ethnic group consisting of Lepchas, Bhutias, Nepalese and the business communities from the plains, communities, cultures, religions and customs though varying with each other intermingle freely thereby constituting a homogenous blend. Sikkim although considered as Buddhist State with monasteries found all over the place are infact minority in population where majority follows Hinduism. In urban areas plainsmen of Indian origin have settled for good while engaging themselves in business. It is worth mentioning that many plainsmen are still continuing to migrate to Sikkim wherein they are officially transferred through their Central Government (Government of India) posts. There are also few thousand Tibetan refugees who have settled in Sikkim.

Lepchas
Lepchas are the original inhabitants of Sikkim. Lepchas refer to themselves as “Rongpas” (ravine – dwellers in their own tongue) and also as “Mutanchi Rongkup” (Mother’s loved ones). Their appearance is Mongoloid, fair skinned and muscular built while they have the short stature. At present they have either adopted the religion of Buddhism or Christianity. Their ancient religion was based on nature worship. Their language known as Rong is highly developed. They carry their traditional knife called “Ban” or “Payak” while wearing their traditional dress “Pagi”. They know what is the best to eat while in forest for survival. Their population is more concentrated in D-Zongu region of North Sikkim.

Bhutias
 Bhutias are the people of Tibetan origin and are also regarded as the ethnic community of Sikkim. It is believed that they had migrated to Sikkim during sixteenth century A.D. and continued to do so, where it picked up momentum with the coronation of their tribal chief as the King of Sikkim. It is believed that they had introduced Buddhism in Sikkim. Marriage between Bhutia royalty and Lepcha hierarchy led to the creation of the “Kazis”. In the North Sikkim the peculiar Bhutia tribes are known as Lachenpas and Lanchungpas where they are well built

Nepalese
Nepalese started migrating to Sikkim in the second half of the nineteenth century A.D. The migration is believed to have followed the entry of Newar businessmen showing expertise in farming as well, who took over the rights to mine copper and mint coins for the Sikkim treasury. Nepalese community as a whole consist of many ethnic tribes with mongoloid features and some Aryan descendants as – well. As the migration of Nepalese was in large numbers, they at present are the major constituent of Sikkimese population and Nepali the Lingua Franca. Nepali settlers introduced the farming under terraced system.