Synopsis There are already a good number of books available on this subject therefore, the present endeavour and its purpose require some explanation. First book focuses 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 suchas ‘Social organization ‘Social Psychology. The various concepts such as ‘social system’ etc. have been well demarcated to make the subject more clear. Secondly the book 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 undergraduates and postgraduate students provided they follow the instruction given in the introduction. In this revised edition some additional material has been added for those students who offer sociology in the preliminary central service 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 this Samaj shastra Ke Siddhant.