Arunachal has 26 major tribes and many sub-tribes living in 3649 scattered villages. Although a number of tribal groups constitue the total population, the density of population is very less. People are Mangoloid stock but each tribe has certain distinct characteristics in language, dress & costume. They have a rich cultural heritage. The People are simple, friendly and hospitable. Their colourful festivals are manifestations of their faith and belief.

The society is patriachal and primogeniture and the fundamental laws of inheritance with variations are not uncommon. They follow endogamy and strictly observe the rule of clan exogamy. Polygamy is socially sanctioned and is practiced by most of them. The people are highly democratic, and each tribe has its own organised institutions that maintain law and order , decide disputes and take up all activities for the welfare of the tribes and the villages. The members constituting these organisations are selected by the people.
The entire population of the state can be divided into three cultural groups on the basis of their socio-politico-religious affinities. It has been found that the tribes of Arunachal are integrated into groups independant of each other, living their separate lives. The common denominators are that the pattern of lifestyle of each is the same and that they follow the same occupation; the societies are casteless; the societies are governed by chiefs and the adults were grouped according to their age for distinct social functions. The young are organised around dormitory institutions to follow the instructions of the older generation.

The WANCHOS inhabit the south-western part of the Tirap district bordering Nagaland. They are fond of wearing decorated headgears and heavy strings of beads on the neck, arms, legs and ears.

The NOCTES inhabit the central part of the Tirap district, to the north of the Wanchos. These people have a long and traditional contact with the people of the neighbouring plains. Many of them are Vaishnavites.

TANGSAS is a common name of a group of people consisting of the Lungchang, Moklong, Yugli, Lungri, Have, Moshong, Rundra, Takhak, Ponthi and Longphi. Each group is subdivided into a number of exogamous clans. These tribes occupy the Changlang district along the Indo-Myanmar front.

The SINGPHOS live on the banks of Teang and Noa Diking rivers and extend towards the southeast into the land of the Khamptis. They are a fine athletic race with developed Mongolian features. They are expert blacksmiths and prepare iron implements of quality. The ladies are good weavers. They are Buddhists.

The KHAMPTIS live to the south of the Lohit district along the Kamlang, Dehing and Tengapani rivers with the Parasuramkund to the northeast and Tirap district of the south. The Khamptis are good craftsmen, enterprising traders and skilful agriculturists. They are Buddhists.

There are three main groups of the Mishmis, viz. Idu, Miju or Kaman and Digaru or Taraon. The Idus, also called Chulikata, by the plains people live in Dibang valley district. With roughly 25,000 members, the Idu tribe is divided into sections, each named after the river by the side of which they live.

It is by the manner of hair doing that the Idus (Chulikatas) are distinguished from other tribes. The front hair is combed down on the brow and then cut straight across from ear to ear. The back hair is collected in a knot.

The Mijis (Kamans) live in the Lohit district, east of the Taraons. Their number is approximately 18,000. The Kamans unlike the Idus, keep their hair long. Their dress is as colourful as it is durable. The Kaman, specially the women, have an admirable sense of colour and pattern. Agriculture is one of the main occupations of these people. The Digarus call themselves as Taraon. They are good agriculturists.

The tribes of the East, West and Upper Siang districts are mainly those classified under the general title of "adis". They may be divided into three main groups: GALOS, PADAMS, and MIWONGS, each of which can again be subdivided into a number of sub-groups.
They are exogamous. Dances are very popular among the Adis. Ponung is their traditional dance, which is also religious in character.
The Galos weave clothes of highly artistic designs and the finest profit is a beautiful skirt with a central pattern of black yarn netted in regular designs of black and white.

The most striking features of the Padam and Minyong society are their highly organized political institution represented by the Kebang or village council and the dormitory. They are forward looking, active and expert weavers.
Along the international frontier in the Tuting area live the KHAMBAS. They are Buddhists and lovers of dance.

The Membas are found along the northern border of Upper Siang district. They are by religion Buddhist.

To the north along the banks of the Sipi river extends the country of the TAGINS. They are also sometimes known as Moyas because of their preference for the shady mountain for their villages. Agriculture is their main occupation.

The Hill Miris inhabiting the lower Kamla valley look attractive in their costume. They tie the hair in a knot just above the forehead. Their women wear attractive "crinoline of cane rings" which serves the purpose of a blouse but now it is not seen in the urban areas.

The Apatamis are settled in a valley in the Centre of the lower Subansiri district around the district headquarters. They live in crowded villages , are expert in wet cultivation and grow paddy and millet in abundance. They have a stable agricultural economy.

The Nyishis are divided into several exogamous clans. The Nyishi men keep their hair long and tie it in a knot just above the forehead and they wear cane bands around the waist traditional dress.

The Hrussos are commonly called Akas which means 'painted' for they have a custom of painting their faces with black marks. They figured frequently in old historical records. They are good traders.

The Khowas (Bugun) occupy 7 villages in Teilga and Bichum valley in the neighbourhood of the Sherdukpens.Buddhism influences the Buguns.

The Puroiks (SULUNGS), live mainly in the high altitudes of Kameng districts. They dress like the Nyishis. The Mijis call themselves Dhamai. In appearance and way of life there is little to distinguish them from the Akas(Hrussos). The Sherdukpens live mainly in the two villages of Rupa and Shergaon in West Kameng district.They are divided into two classes, the Thongs and the Gheos. The Sherdukpens are good agriculturalists and traders. Their religion is an interesting blend of Buddhism and religious beliefs. There are the gentle and cultured Monpas of West Kameng Districts who received Buddhism from Padma Sambhava .