In the recent theory of sport socialization, studies from the viewpoint trying to regard socializee (=socializing individual) as active have increased. However the situation has been in disorder, because methodological pluralism and untheoretical studies have prevailed. A major cause of the situation is thought that the meaning of "active" is ambiguous. So the purpose of this study is to find a theoretical framework to put the active theory of sport socialization in order, expecting the concept "subjecthood" to offer a key to this problem. Sociological theories adopted in this study are Schutz's, Luhmann's, and Mead's. The concept "subjecthood" contains two main meanings of "subjectivity" and "independence" which is synonymous with "autonomy". The meaning as subjectivity is found in Schutz's theory. It is the autonomous function of "Relevance" (or "System of Relevance") which is the cognitive base of action. On the other hand, the meaning as independence is found in Luhmann's theory, and it bases on the function of Relevance. And subjecthood found in Mead's theory is the meaning of autonomy as the function of "I". This also bases on the function of Relevance, and contains the creative or the reformative character of socializee in a problematic (=conflicting) situation. All of them have characters of the mechanism of action accomplishment, and have changeable characters in quality. Therefore viewpoints of the study on the active theory of sport socialization are pointed out as follows: 1) On socializee's actions on subjecthood which contain the cognitive situation on subjectivity in sport contexts. 2) On the change in quality of sociaizee's subjecthood in sport contexts. In either case, it is important to pay attention to the problematic situation of socializee. The study on 1) is a key to the one on 2). Actions on subjecthood are such ones as role-negotiation,sport-role-adaptation, sport-role-making, sport-self-actualization, sport-role-distance, sport-transfer, and sport-dropout, which are based on independence (=autonomy).