Migration is the third component of population change, the other two being mortality and
fertility. The United Nations Multilingual Demographic Dictionary defined migration as ‘‘a
form of geographical mobility or spatial mobility between one geographical unit and another,
generally involving a change in residence from the place of origin or place of departure to the
place of destination or place of arrival. Such migration is called permanent migration and
should be distinguished from other forms of movement which do not involve a permanent
change of residence.’’ Assam is situated in the north-east of India- bordering seven states and
two countries viz. Bangladesh and Bhutan. The large volume of influx of migrants (both
interstate and international migration) have modified the population structure of Assam in
respect of ethno-religious composition, occupation structure etc and host of associated
population problems in changing socio-political disturbances like ethnic clash etc. This paper
is divided into three sections. This paper first analyze the decadal growth of population and
population density in Assam and in India, from 1901-2011. This paper then evaluates the
growth of population by religion in Assam and in India, during 1951-2011. This paper also
assesses the spatial distribution of migrants from other states of India and spatial distribution
of migrants from outside India into Assam, during 2001.