Internal migration is a important element of population redistribution and equilibrium. Human mobility within the national boundary is receiving considerable attention in recent decades. The main objective of the study is to explain the changing pattern of internal migration in India over the period 1971 to 2001. Further, an attempt has been made to find out the various determinants causing the changing pattern of migration. The rate of migration among major states of India in last two decades is also worked out through transition probabilities using a stochastic model. In all the four censuses, rural-rural migration was found the dominant migration stream in India. Employment for male and marriage for female were found to be the main reasons for migration respectively. Maharashtra and Madhya Pradesh lead among all in-migrating states, while the states Utter Pradesh and Bihar occupied top place among out-migrating states.