The population of Arunachal is 8,65 lakhs according to 1991 census .and is scattered over 12 towns and 3649 Allages. There are 26 major tribes and a number of sub-tribes inhabiting the area. Most of these communities are ethnicafly similar, having derived from and original common stock but their geographical isolation from each other has brought amongst them certain distinctive characteristics in language, dress and customs. Three Cultural Groups broadly, the people may be divided into three cultural groups on the basis of their socio-refigious affinities. The Monpas and Sherdukpens of Tawang and West Kameng districts follow the lamaistic tradition of Mahayana Buddhism. Noted for their religious fervour, the villages of these communities have richly decorated Buddhist temples, locally called'Gompas'.Though largely agriculturists, practising terrace cultivation, many of these people are also pastoral and breed herds of yak and mountain sheep. Culturally similar to them are Membas and Khambas who live In the high mountains along the northern borders. Khamptis and Singphos inhabiting the eastern part of the state are Buddhists of Hinayana sect. They are said to have migrated from Thailand and Myanmar long ago and are still using ancient scripts derived from their original homeland.

The second group of people are the Adis, Akas, Apatanis, Bangnis, Nishis, Mishimis, Mijis, Tangsas etc, who worship the Sun and the Moon God, namely, Donyi-Polo and Abo-Tani, the original ancestor for most of these tribes. Their religious rituals, largely coincide with the phases of agricultural cycles. They invoke nature deities and make animal sacrifices, They traditionally practise jhurrdng or shifting cultivation. Adis and Apatanis extensively practice wet-rice cultivation and have a considerable agricultural economy. Apatanis are also famous for their paddy-cum-pisciculture. They are specialised over centuries in harvesting crops of fish along with each crop of paddy.

The third group comprises Noctes and Wanchos, adjoining Nagaland in the Tirap district. These are hardy people known for their strictly structured village society in which the hereditary village chief still plays a vital role. The Noctes also practise elementary form of Vaishnavism.

The people of Arunachal Pradesh have a tradition of artistic craftsmanship and sense of aesthetics manifested through a variety of crafts such as weaving, painting, pottery, smithy work, basket making, wood carving etc.Monpas are known for their artistry in weaving carpet and making painted wooded vessels. Beautiful rugs are also woven in the Adi area. Vivid colour and exquisit patterns are the hall mark of their weaving. Apatanis, Hill Miris and Adis make attractive articles in cane and bamboo. The wanchos are famous for their wood and bamboo carved figurines. They also make intricate necklaces of colourful beads the width of which indicate the status of the person they adorn. 

Festivals are an essential part of the sociocultural life of the people. The festivals are connected with agriculture and celebrated with ritualistic gaiety either to thank God for His providence or to pray for good harvests.

Some of the important festivals are Mopin and Solung of Adis, Lossor of Monpas,Sherdukpens and Boori-Boot of Hill Miris, Dree of Apatanis, Si-donyi of Tagins, Nyokum of Nishis, Reh of ldu Mishimis etc. Animal sacrifice is a common ritual in most festivals.

Dances form a vital element in the zest and joy of living of the tribals. They vary from highly stylized religious dance dramas of the Buddhists to the martial steps and colourful performances of the Noctes and Wanchos. Among the Adis, dance had evolved almost into an art form mainly for entertainment and recreation. The 'Ponung' dance of Adis is performed by teams of young girls in perfect rhythmic unison.Similar group dances in colourful costumes are performed by the Nishis and Tagins of Upper and Lower Subansiri.

In Arunachal's rich and colourful flora and fauna orchids find a place of pride. Out of about a thousand species of orchids in India, over 500 are to be found in Arunachal alone. These are colourful, spectacular and some bear exotic names such as Sita-Pushpa and Droupadipushpa which were believed to have been worn by Sita and Draupadi for ornamentation.
Some of the orchids are rare and classified as endangered. Arunachal Pradesh Forest Development Corporation has established an Orchid Research and Development Station at Tipi in West Kameng district for a propagation and conservation of these species. This centre has established a laboratory for orchid seed and tissue culture for this purpose. In addition to Orchidarium at Tipi, two orchid conservation sanctuaries have been established at Sessa and Dirang in West Kameng district.
The wild life of Arunachal is equally rich and varied. Elephants and tigers abound, especially in the grassy foothills and the leopard and jungle cat are quite common. The white- browed gibbon is found in Tirap and Lohit districts and red Pandas and musk deer in the higher ranges.
The 'Mithun' (Bos Frontails) exists both in wild and semi- domesticated form. This animal has religious significance and has intimate relation with sociocultural life of the people. Traditionally, the mithun is a unit of wealth and is allowed to move freely in the jungle till it is either used for food on festive occasions and marriage feasts, or for barter.
Arunachal Pradesh is also the happy home of the great Indian Hornbill, the extraordinary bird with an inordinately large beak. The white-winged wood duck, a rare endangered species, has been sheltered in Namdapha National Park.
Four wildlife sanctuaries at Pakhui, Laii, Itanagar and Namdapha had been set up by 1979, covering an area of 3000 sq. kms. The Mehao wildlife sanctuary was established in the Sixth plan and Namdapha sanctuary was upgraded to the status of a National Park in 1983.
'Project Tiger' was also launched in Namdapha in 1983. The Mouling Reserve Forest in East Siang district, covering an area of 483 sq. kms. has been declared a National Park in 1986.