Tribal peoples in India have been the focus of scho­larly attention, particularly in the fields of anthropology for about a century, for being excluded, marginalised and vulnerable. There have been attempts to bring this 'excluded' section of the society to so-called mainstream society through a number welfare measures and programmes. There are evidences of tribals being assimilated and integrated to the nation-state; and their culture, custom, economy, religion, politics are reported to have been changed because of the impact of modern education, migration-led enculturation, culture contact, technological advancement, market economy and influence of dominant culture. So, the idea of tribals being 'homogenous group' is no longer exist instead many of the tribals are now become a heterogenous group who are constantly changing its institutions of kinship, family, marriage, economic, politics, laws, decision-making, beliefs, worldview, healthcare, etc. and assimilating to the modern society. This compendium titled Tribal Transformation and Development in Eastern India, consisting of 14 articles, attempts to highlight the nature of transition among the tribes of India and will be useful for academician, researchers and policy makers working on tribal issues.