Mishima Yukio's Literary World and Sports : focusing on The Realistic Argument on Sports Mishima Yukio is known as aestheticist for his major work Kinkakuji until 1960s when there was a drastic change in the world of his work. As his interest in reality had been increased, he had become more and more radical nationalist, and finally he committed hara-kiri with clamoring for the revival of militarism and the Emperor system. This change of his ideology was reflected in the world of his work. Then, what was the motivation of the change? This thesis had been started from this question. I have thought of that motivation associated with his interest in sports in this thesis. This is because the most noteworthy change in that transition period was his concern for sports, looking back on Mishima Yukio's real life. Thus, in and around The Realistic Argument on Sports which is condensed into his interest in sports, I analyzed the detailed process that he tried to remodel the body with body-building and boxing, and then he started kendo so as to reconstruct the mind. As a result, I had found that he had faced the incongruity between body and mind since he had been deep into the world of sports so that his yearning for or blind faith in body, power, or absolute authority had been intensified. In addition, I had figured out how this change had effects on the world of his work or his ideology.