The purpose of this study is to understand the reason why ‘the concept of education’ of Dewey is defined based on its correlation with ‘the concept of life’, through ‘the concept of inquiry’ of Dewey. In the philosophy of Dewey that incessantly has set out the ‘totality of life’, his all concepts are formed based on human behaviors. That is, all concepts such as ‘experience’, ‘habit’, ‘value’, ‘growth’, ‘education’, and ‘inquiry’, and so on are established only when there are human actual ‘behaviors’, thus ‘the concept of life’ of Dewey can be defined as the ‘self-renewing process’, and accordingly the ‘life’ to him can proceed with in a ‘continued and accumulated form’. However, since ‘the concept of inquiry’ among all his concepts is interpreted into the same to the meaning of the ‘reflective thought’, it causes a question of what association ‘the concept of inquiry’ of Dewey has with ‘the concept of life’ of Dewey. Prior studies interpreted ‘the concept of inquiry’ only means ‘a reflective thought’, by connecting it to the educational method of school, which overlooks its correlation with ‘the concept of life’ of Dewey. Strictly speaking, Dewey criticized the ‘Dualistic World’ that classified the human life into many strata and understood them as ‘orientation’ and ‘sublation’, so if the ‘inquiry’ is defined as the same meaning to that of ‘the reflective thought’, it will be difficult to determine what correlation ‘the inquiry’ has with all other concepts such as ‘experience’, ‘habit’, ‘value’, ‘growth’, and ‘education’ in the ‘totality of life’. As a matter of fact, it is possible to define ‘the inquiry’ as ‘the reflective thought’ within the special setting called ‘school education’ to think of the inquiry as the effective ‘educational method’, but it causes a limit in understanding on what logical bases ‘the inquiry’ has the correlation with all concepts of Dewey. The author tried to redefine the meaning of ‘the concept of inquiry’ described in the Logic written by Dewey as ‘the existential maintenance method’ of organisms centering around humans to expand the previous meaning of ‘the concept of inquiry’ that had just meaned ‘the reflective thought’. Dewey also describes the matrix of inquiry as “THE EXISTENTIAL MATRIX OF INQUIRY: BIOLOGICAL”, and “THE EXISTENTIAL MATRIX OF INQUIRY: CULTURAL” respectively in Chapter Ⅰ, Section II to III, of the Logic, in order to emphasize the existential aspects of the inquiry. In addition, in Chapter Ⅰ, Section Ⅰ, “THE PROBLEM OF LOGICAL SUBJECT-MATTER”(Dewey, 1964: 3-4), Dewey describes the inquiry as ‘the primary inquiry’, in order to emphasize that ‘the inquiry’ is ‘the existential concept’ before it is considered as ‘the reflective thought’, in terms of the ‘fundamental aspect’ that the reflective though is well matched to the human organism because the human organism maintains its existence by ‘the reflective thought’, arguing that the reflective thought should not be defined as the one limited in ‘the problem solving’ which ‘the reflective thought’ that means ‘the inquiry into inquiry’. The inquiry to Dewey means ‘the existential maintenance method’ of organisms centering around humans, so if this concept is generalized, it means ‘all forms and patterns’ of life of organisms. When ‘inquiry’ is defined as ‘existential maintenance method’, it is possible to determine on which base ‘the concept of life’ of Dewey was formed. The concept of life of Dewey consists of two key factors such as ‘environment’ and ‘renewing’. Here, ‘environment’ does not mean what is given like nature, but means ‘the field of existential maintenance’ of an organism created through interaction between the organism and nature, while ‘renewing’ means the ‘self-maintaining process’, which enables the argument reasonable that an organism has the forms of ‘continued maintenance’, and ‘restoration’ that incessantly converts ‘imbalance’ to the ‘balanced status’ in order to adapt to the ‘environment’. Strictly speaking, these two factors cannot be reasonable if the ‘behavior’ of the organism is ‘sporadic or temporal’, and only can be reasonable when the behavior proceeds in ‘the form of continuation and accumulation’. What leads the ‘behavior’ of the organism to the ‘continued and accumulative form’ results from its ‘existential maintenance method’, which corresponds to ‘the concept of inquiry’ of Dewey. Thus, ‘the concept of life’ of Dewey can be found to have been formed by the ‘inquiry’ having its definition based on its fundamental concept. Like this, if ‘the concept of life’ of Dewey is to be understood through ‘inquiry’, it comes to be possible to determine why the ‘education’ is defined based on its correlation with ‘the concept of life’, for Dewey. That is, if we look at the prior studies regarding the correlation between the ‘education’ and ‘the concept of life’ of Dewey, it can be found they just understand the ‘life’, ‘education’, and ‘growth’ as synonyms by inferring from the following contents described in the Democracy and Education through the syllogism: “Life is development, and that developing, growing, is life. Translated into its educational equivalents, this means that the educational process has no end beyond itself; it is its own end; and that the educational process is one of continual reorganizing, reconstructing, transforming”(Dewey, 1916: 105), “Since in reality there is nothing to which growth is relative save more growth, there is nothing to which education is subordinate save more education”(Ibid. : 106) instead of finding out the ‘fundamental reason’, that is, on which logical base, the ‘education’ is defined to have the correlation with ‘the concepts of life and growth’ of Dewey. Accordingly, in their studies, ‘inquiry’ is only referred to as the ‘reflective thought’ in terms of the ‘educational method’ of school education while the ‘inquiry’ is rarely associated with those concepts such as ‘life’, ‘education’ and ‘growth’. As a result, if the ‘inquiry’ is defined as ‘the existential maintenance method’, it can be determined that for Dewey, ‘education’ necessarily has the correlation with ‘the concept of life’.