East Kameng District was created only after House-listing Operation of 1981 Census. As per re-organisation of District Act, 1980, Kameng District was divided into two districts namely, East Kameng and West Kameng District. District headquarters of East Kameng is Seppa which was subdivisional Head Quarters of erstwhile Kameng District. The newly constituted East Kameng District comprises of two Subdivisions namely, Seppa and Chayengtajo.

The name, Kameng is derived from the Kameng river, a tributary of the Brahmaputra. Till 1914, the District was a part of the Darrang District of Assam. By a Government of India, Notification of 1914, the area covered by this district became a part of the “ Western Section” of the ‘North East Frontier Tract’. In 1919, the area covered by Balipara Frontier Tract was divided into ‘Sela-Agency’ and the Subansiri Area and its headquarters continued to beat Charduar. In 1954, Sela Sub-Agency was renamed as the Kameng Frontier Division and its headquarters was later shifted to Bomdila. In 1965 Kameng Frontier Division was  renamed as Kameng District. In May, 1980 the District was bifurcated into two parts namely, East Kameng District (Erstwhile Seppa Subdivivision) and West Kameng District (Erstwhile Bomdila Subdivision). The area of East Kameng District is 4,134 Sq. Kms. Details of the changes due to reorganization of the district have been shown in Appendix I.

At the time of taking 1971 Census, the area covered by the district formed a part of the North East Frontier Agency which was then constitutionally a part of the State of Assam. The agency was directly administrated by the President of India trough the Governor of Assam as his agent. In 1972, the Agency was made into a Union territory and renamed as Arunachal Pradesh. A Chief Commissioner, with his headquarters at Shillong, was made the Administrator of this new Union Territory. On the 15th day of August, 1975, Legislative Assembly was constituted in the Union Territory of Arunachal Pradesh with the Chief Minister and Cabinet of Four Ministers to assist the Lt. Governor appointed on the same day as the Chief Administrator of Union Territory. The Headquarters of the Union Territory was shifted to the capital sight at Itanagar in Lower Subansiri District in year 1974.

The Panchayat Raj was introduced in the District with the North East Frontier Agency, Panchayat Raj regulation, 1967. Under this regulation(1) the Gram Sabhas exist at the village level, (2) the Anchal Samities cover the levels of Blocks, (3) the Zilla Parishad opeates at the District level and (4) the Agency council(later on renamed as Pradesh Council in 1972 when the Council was renamed as Arunachal Pradesh) operates at the Agency level. The agency council/Pradesh Council, however, has lost its existence with the formation of Legislative Assembly in the Union Territory. The regulation provides for effective participation of the people in the administration of the Union Territory through the institutions set up under the Panchayat Raj Scheme. The Anchal Samities and the Zilla Parishad function as advisory bodies only. |The Gram Sabhas or the village Councils have, however, some administrative powers within certain limitations.

The East Kameng District is divided into two subdivisions namely, Seppa and Chayengtajo. Administrative responsibility of Seppa Subdivision directly lies with the Deputy Commissioner General in a Subdivision is under the charge of an Addl. Deputy Commissioner). The Deputy Commissioner, however, is the head of the entire district administration. A circle is treated as the lowest unit of administrative machinery which is looked after by a Circle Officer. At present there 13 circles in the East Kameng district. A circle is defined as a group of villages and not as a territorial unit.  Area figures below the level of the district are not available. The villages have their own customary administrative system in the form of tradition village councils. The Assam Frontier (Administration of Justice) Regulation, 1945 authorises the village councils to settle all civil cases and certain criminal cases falling within their jurisdictions. Besides, the Deputy Commissioner is invested with the powers of sessions judges and some Officers are given magisterial power Assam High Court has jurisdiction over the District Courts and hold appellate and revisional power. The Arunachal Police assists the district authorities to maintain law and order. But since the department is very new the number of police personnel is not sufficient to cover large area, this however, does not adversely affect the administration of justice.

Since 1975, the Union Territory received a full-fledged legislative Assembly and the members (MLA) are elected on the basis of universal adult Franchise systems of secret ballot who are participating in the administration of the Territory/District, besides the Panchayat Raj members.

As regards composition of the people and their history, it may be mentioned that the district is predominantly inhabited by the Scheduled Tribes of Arunachal Pradesh. The Scheduled Tribes population of the district accounts for 87.25% of the total population of the district. The Bangnis and Sulungs are the major tribes of the district. The history of all these tribes including their migration, material and socio-cultural and other allied aspects have been discussed in the District Census Handbooks of 1971 Census in respect of Kameng district