About the Book : There are already a good number of books available on this subject therefore the present endeavour and its purpose require some explanation. First book focusses on the study of various aspects of social structure as such and not culture and personality, which however are not ignored, but are mainly the domain of Cultural Anthropology and Social Psychology. The various concepts such as 'social organisation,' 'social structure', 'social system' etc. have been well demarcated to make the subject more clear. Secondly the book has been written in such a way that it can be useful both to the under-graduates and postgraduate students provided they follow the instructions given in the introduction. In this revised edition some additional material has been added for those students who offer sociology in the preliminary central services Examination of the UPSC. Thirdly, it may be mentioned, that the National Book Trust of India, New Delhi, due to the well presentation of the matter in the book, gave special subsidy for the publication of its Hindi version which was brought out in 1988 under the title Samaj Shastra Ke Siddhant. It is hoped that the book will be useful for students as well as teachers of Sociology, Social Work, Social Administration etc. About the Author : Prof. G.R. Madan, M.A. (Econ. & Social.), Dip. In Commerce, LL.B., Ph.D. (b. 1923) had been teaching in the Department of Sociology and Social Work, University of Lucknow till his retirement in 1984. A widely travelled person Prof. Madan has privilege of working with distinguished Sociologists viz. Dr. Radhakamal Mukherjee, Dr. Harold F. Kaufman and Prof. S.L. Andreski at J.K. Institute of Sociology and Human Relations, University of Lucknow, Social Science Research Centre, Mississippi State University (USA) and University of Reading (UK) respectively. A keen researcher, Prof. Madan visited various universities to deliver lecturers. A prolific writer Prof. Madan has over two dozen outstanding books on India's social and economic problems to his credit, besides a score of articles published in reputed journals and magazines. He has been associated with a number of social welfare and voluntary organisations including Indian Council of Social Welfare, Radhakamal Mukherjee Memorial Society and Associate of Voluntary Social Agencies and Workers (India).