This thesis sees through Park-Young-Hee`s novel and criticism with the conversion and pro-Japanese after the latter half of 1930`s. Above all, conversion is not mere matter, and the general thought-regeneration. And the term of conversion is not given to us. At this point this thesis sees through his manifesto, his novel 「Light and Darkness」, a note 「A cell」. And furthermore inner crack-shape of his national literature-theory in the period of new-system. His manifesto of conversion focuses art instead of ideology. But「Light and Darkness」shows the point of resistance to it. A proposition, `I ought not to be failed` is that. Moreover the work was published in the period of the national literature-theory. At this point the mentality of a convert is never simple. Especially「A Single Room」emphasizes the class-ideology. The reason why a head of criticism and work ought to be considered in the study of conversion-literature. But his criticism confronts with the great turnover in the period of new-system. Above all deflection is in existence among his works. The national literature-theory of his is based on the mere dichotomy. Besides the dichotomy as `ideology/arts` `material/soul` `the western individualism/the oriental Japanese-spirits` are in existence. Really, 「A Single Room」emphasizes the dialectical thought. But his national literature-theory does not considers the mutual interrelation. The assertion that an individual must be broken to the state is merely repeated. Because he does not raise a question to the political structure in a new-system. Especially the national literature-theory and the objective literature-theory coexist, At this point we must not understand conversion and pro-Japanese plainly.