It is situated in the North-Eastern part of India with 83743 sq. kms area and has a long international border with Bhutan to the west (160 km), China to the north and north-east (1,080 km) and Myanmar to the east (440 km). It stretches from snow-capped mountains in the north to the plains of Brahmaputra valley in the south. Arunachal is the largest state area-wise in the north-east region, even larger than Assam which is the most populous.

It is situated between latitude 26° 30' N and 29° 30 ' N and longitude 91° 30' E and 97° 30' E. Itanagar is the capital of Arunachal Pradesh and located at an altitude of 530 meters above MSL. It is named after Itafort meaning fort of bricks built in 14th century A.D.

Nature has been exceedingly kind and has endowed this beautiful State of Arunachal Pradesh with diverse forests and magnificent wildlife. The richness of life forms i.e. the flora & fauna that occur in these forests presents a panorama of biological diversity with over 5000 plants, about 85 terrestrial mammals, over 500 birds and a large number of butterflies, insects and reptiles. Such an unparalleled occurrence of life forms can be attributed to the peculiar location of the State which is at the junction of the Paleoarctic, indo-Chinese, and Indo-Malayan bio-geographic regions , Biotic elements from all these regions occur in this state making it very rich in floral & faunal resources.

The vegetation of Arunachal Pradesh falls under four broad climatic categories and can be classified in five broad forest types with a sixth type of secondary forests. These are tropical forests, sub tropical forests, pine forests, temperate forests and alpine forests. In the degraded forests bamboos and other grasses are of common occurrence.