This study examines conversion in the works of Shigeharu Nakano, a Japanese proletarian poet. The issue of conversion and conversion literature is a thorny problem in the history of modern Japanese philosophy and literature. Its use is not limited to the proletarian literature period during Showa but it flows at the base of the structure of modern Japan from the Daisho period to the Showa period. Conversion in Nakano`s works as a research theme is especially difficult to handle. The fact that it means different things to different critics proves the point. In other words, as Nakano`s concept of conversion is vague and its boundary is abstract, we still need to decide which works can be classified as conversion works. In this study, the author set the scope of Nakano`s works containing conversion to be more inclusive. The result can be summarized as follows.