In this study, we have discussed the relationship of theory and practice in psychology. The purpose of this study is that critiques previous studies of theory and Practice, which include that of a general academic society and the Japanese Research Association of Psychology Science (JRAPS), and that presents an alternative perspective of relationship of theory and practice. At first, we define the discussion or theory and practice, which wc examine in this study as "a practicity of theory" : our analysis focus on the process that is not practitioners' acceptation of theory, but how researchers relate their theories and studies to practice. Then, we review Habermas's idea of the relationship of theory and practice and of knowledge and interest, which contains three classifications, technical knowledge-interest, practical and emancipatory one. And on the basis of these ideas, we construct a model of the relationship of theory and practice. This model contains two processes, the process of the theory's own origines and application. The former is the process of constructing theory, the latter is the process of using theory for practice, in a word, enlightenment. In addition, each processes has two aspects, the process of constructing theory has aspects of researchers themselves criticize their theoretical framework from the perspective of practice and emancipate the perspective of practice, that of enlightenment also has two aspects of problem-solving in compliance with practice and enlightenment to practice. We examine and classify the previous studies on the basis of this model. As a result, we point out following facts : (1) most discussions in the domain of the general academic society are only basis of problem-solving in compliance with practice, then they are lead to only technical knowledge-interest. (2) several researches in JRAPS contain another aspects from general discussion of theory and practice, some has self-reflection of their theoretical frameworks, other has enlightenment perspective. And we critique these discussions and researches, present our own studies, whose perspectives would be lead to emancipatory knowledge-interest, as, alternative one. Finally we emphasize the importance of self-reflection, which researcher improve their own the theoretical framework of study, and the importance that when we study various psychological problem, we must take into account a value of our subject or practice.