I try to examine dynamic theories in British social anthropology, especially in works written by B. Malinowski, A. R. Radcliffe-Brown and R. Firth. On the one hand, Molinowski criticized 'diffusionism' which had been insisted by W. T. Perry and E. Smith, denying their reconstruction of history and their inclination to the origin hunting, and so on. On the other hand, we can regard his theory as a kind of diffusion theory. But the characteristic which I think very important in his theory is his emphasis upon psychological realities or powers, i. e. psychological point of view, and his revaluation of surviving historical residues. Radcliffe-Brown laid stress on the concept of structure, since he took a sociological point of view. He offered a comparative analysis of social structure. Thus he divided the study of social structure into three divisions. He said as follows: 'There is a third, the investigation of the processes by which social structures change, of how new forms of structures come into existence.' Both the concept of structure and the notion of structural change have far reaching theoretical influences. Along these lines, Firth presents the organizational aspect of social relations in addition to structural and functional aspects. He thinks organizational aspect as it is the necessary complement to the analysis of the structural aspect and it helps to give a more dynamic treatment. Fathermore he points out that the organizational aspect implies personal evaluations and selections. In relatioa to what mentioned above, he makes clear the difference between structural and organizational change. Therefore we must examine in the first place the organizational change because of its characteristic of humanistic coefficient.