This study aims at examining the nature of teaching profession over which there has been quite confusing controversies. For that purpose, four main sub-themes were dealt with: justifiability of a claim for professionalization of the teaching profession; de-professionalization of the teaching profession in reality; factors causing de-professionalization of the teaching profession; and a new possible nature of the teaching profession. I carried out the study both through logical speculation and using practical sources. Major arguments about each of four sub-themes are as presented below. Concerning the first sub-theme, I emphasized a high degree of difficulty in educating in the course of justifying professionalization of the teaching profession. But, the argumentation was made on the assumption that education would be performed in conformity with its ‘original’ norms. Related to the second sub-theme, it was revealed that we could hardly find the evidences saying the teaching profession held professional status in reality. In order to see whether the teaching profession met standards required for professional status I employed six criteria, while placing more emphasis on teachers' use of professional knowledge and skills. For the third sub-theme, I identified the educational and non-educational factors which seemed to bring about de-professionalization of the teaching profession. Among those factors were included ambiguity of educational phenomena by its nature, popularization of education, ’chaos’ of education value, routinization of educational activities, bureaucratization of educational managements, trivialization of educating. The ways the teaching profession become de-professionalized under the influences of those factors were discussed. Lastly, dealing with the fourth sub-theme, I suggested a newly-determined nature of the teaching profession which was likely to be acknowledged more reasonably. But, the nature of the teaching profession suggested thereby must be considered as a tentative one and be open to further debates and revisions. It was “ethical and devoting profession pursuing specialty.”