Sikkim is a multi-ethnic state. Broadly, the population can be divided into Tribal and Non- Tribal groups. The people from the plain mostly involved in Trade and services represent a marginal group. As per the 2001 census of India, the total population of the state is 5, 40,493, whereas in 1991 it was 4, 06,457 only. Decadal population growth has gone up for 1991-01 to 32.98% .as in 1981-91 it was only 28.47%. The overall density of population in the state is 76 per sq. km. East district is the most populated as North's density with only 7, is least populated. Sex ratio (Females per thousand Male) is 875. The State (at National Level) has the literacy rate 69.68% (16th), Fertility rate 2.75 (12th), Infant Mortality rate 52 (13th), Index of Social & economic infrastructure 108.99 (9th), Plan expenditure in social sector 45.38% (4th), Access to safe drinking water in % of households 73.19 (6th), Per capita consumption of electricity 182 Kw H (25th), & Per capita income is Rs.11,356 ( 14th).There are 166 Panchayats and 453 Revenue Blocks , which comprise of 32 Assembly Constituencies.

It is an established fact that the earliest inhabitants of the land were the Lepchas. The Lepchas were food gathering people who claimed they came from Mayel, a legendary kingdom on the slopes of Khangchendzonga. They lived in close harmony with nature, for she gave them all they needed—the flesh of animals, fruits, medicinal herbs, honey and fibres that could be woven in fabric. They called themselves, Rong Pa literally meaning ravine folk or the Mutanchi, meaning the beloved people of the mother earth.

The Lepchas also call themselves as Rongkup (Children of Rong) followed Bongthing and worshipped the spirits of mountains, forests and rivers that is to say nature in general. They are a simple people in rhythm with nature. They speak Lepcha language - the most ancient language. The Lepchas are mongoloid in appearance with oblique eyes small in stature and fair in complexion who are amiable, cheerful, hospitable, shy, good humoured, sociable, indolent, docile and peace loving. Most of them are concentrated in the Dzongu valley of North Sikkim. They used to live on hill tops "which cannot be reached easily”. They lived in hunting, fishing, trade and later agriculture. They are also good entomologists in identifying the names and behaviour of the wild animals, birds, insects, fishes, frogs, medicinal herbs and also at ease to distinguish all the edible roots, bulbs, fruits and plants of the jungle from that of the poisonous ones. The Lepchas are expert weavers and cane craftsmen and very handy with the bow and arrow. These days they follow Buddhism and some are converted to Christianity.

The Lepchas have their own script and language. Agriculture is their main occupation and cardamom, cinnamon, paddy and oranges are their main crops. The Lepcha tribe is now spread in all parts of Sikkim because of network of roads, communications, education and seeking government jobs. They are marching forward with the rest of the fellow citizens of the State.

The language of Lepchas is recognised by the Government of Sikkim and is taught up to Graduate level. They have held many important posts during the rules of various Maharajas of Sikkim and now they have come to the level of bureaucrats, ministers and hold other covetable posts under Government of Sikkim. In Sikkim legislative Assembly, 12 seats are reserved for Lepchas and Bhutias.

The Bhutias came to Sikkim sometime in the 15th century and are mainly descendants of the early settlers from Tibet and Bhutan. They accompanied ancestors of the first Chogyal Phuntsog Namgyal. They settled in higher altitude, driving the Lepchas into the forests and lower valleys. The Bhutias are sturdy and well built with a good physique and mongolian features. The Bhutia villages are big and are arranged in tiers on undulating hills. They are followers of Buddhism and the monasteries occupy predominant place and play an important role in the socio-cultural life of the Bhutias. They prefer to live in patriarchal joint family. The Bhutia families are known as the category of village headmen and Landlords or Kazis.

The Bhutias promoted Jhooming (shifting) cultivation as they possessed plenty of cultivable lands and sowed paddy, kodo (millet), maize and other cereals. The Bhutias have imbibed the Tibetan Civilization in regard to their dresses, ornaments, religion and scripts. Their language is Sikkimese language (Bhutia language) and they follow Buddhism. The Bhutia language is taught up to degree level. University of North Bengal has included Bhutia, Lepcha and Limboo languages since 2000 as Modem Indian languages. Sikkimese Bhutia language is a State recognised language.

Monasteries, prayer flags, prayer wheels and chortens are much a part of the lives of the Bhutias as faith in reincarnation. Earlier every Bhutia family had a male member who joined the monastery and led the life of a monk because the monks are considered the intellectual elite of the Bhutia Society and education was the sole preserve of the monasteries.

The Bhutias are fond of their CHAANG - an indigenous drink which is a preparation from fermented millet served in a bamboo containers called TONGBA with hollow bamboo pipe. It is an indispensable part of every Sikkimese ceremony. The Bhutias are expert weavers and the hand-woven rugs, carpets and blankets are very famous and quite high in demand. All Bhutia art and paintings are derived from Buddhist spirituality and the most famous are the THANGKAS. The Bhutia craftsmen are known for the intricately carved statues, objects of worship and Choktses-the carved tables.

The Bhutia Calendar follows the Tibetan Buddhist calendar which has 12 years and 60 year cycles. The 12 years are named after 12 animals and the combination with 5 elements (namely wood, water, iron, fire and earth) is used for the 60 year cycles.

Today the Bhutia society is 'undergoing subtle changes owing to education, culture, social events, government jobs, political and constitutional safeguards and government employment. Many of them are serving in very high administrative posts and Ministership. The Bhutias along with Lepchas have 12 seats reserved in the State Legislative Assembly.

The Nepalese comprise over 70 percent of Sikkim’s population. They began to settle down in Sikkim since the last two decades of 19th century. Their settlement in Sikkim was encouraged by the British. The Nepali community of Sikkim is a mélange of various castes and a highly stratified society, speaking their own vernacular and having a culture of their own. They are divided into the Bahuns, Chettris, Newars, Mangers, Murmis, Rais, Limbus, Tamangs, Gurungs and scheduled caste namely Kamis, Damais and Sarkis. The New Nepali settlers were invited and brought as an agrarian force and promoters of sharecrops. They introduced the terrace farming to give the landscape an unimpeachable beauty and a sensible agricultural system which suited very much the terrain of Sikkim.

Nepali language-the lingua-franca of the State is spoken by all communities in Sikkim. This language is widely taught in schools and colleges in the State. It has received Constitutional recognition in the year 1992 and is included in the VIIIth schedule of the Constitution of India. Nepali language and literature are taught upto Ph.D level in Calcutta University, University of North Bengal, Allahabad and Banaras Hindu University.

It is essential here to point out that there are many people from other states of India settled in Sikkim. Firstly, the Marwaris who belong to business community, who came to promote trade via Sikkim to Tibet and later also in Sikkim. They have settled in Sikkim since long. Besides Marwaris there are people from Bihar and Haryana. These communities are also involved in business and other associated works and allied professions. Rest of the people from other States are employed in Central and State Government jobs and in other professional areas like teaching and other technical areas.

It is also interesting to note that there are many Tibetans settled in Sikkim and their status is same as prevalent in other parts of the Country. Still the Tibetans feel comfortable and are very much at home because of the similar culture, language, traditions, religion followed in Sikkim by the ethnic Sikkimese Bhutias and Lepchas.