This thesis is a study on dualism in Cy Twombly(1928-2011)’s series of Lepanto. Twombly made his debut with his scribble-like works in the 1950s when Abstract Expressionism enjoyed its golden age. In the New York art world where American Type Modernism was prevalent, Twombly was not permitted, and thus he had been a forgotten artist for a long time. After the advent of postmodernism, however, Twombly has been “rediscovered” continuously and become one of the most expensive artists. Hostility and hospitality, between these, does Twombly’s dualism exist. The subject of the series of Lepanto, the Battle of Lepanto, was the naval battle in which a fleet of the Holy League, a coalition of Spain, the Republic of Venice and the Papacy, decisively defeated the main fleet of the Ottoman Empire in 1571. Because the pivotal point of power between the East and the West had changed due to this event, the Battle of Lepanto has been considered as the crucial turning point of conflicts between the East and the West. Traditionally many Western artists have painted the Battle of Lepanto as a grand painting showing off the glorious triumph. However, it is the scrawl-like traces that Twombly’s series of Lepanto displays. Therefore, it can be said that not as representing the monumental event as it is, but as doodling it lightly, Twombly intended to break down the traditional binarism ― the East and the West, by extension, triumph and defeat, life and death. In the series of Lepanto, the galleys signify masculinity and the sea implies femininity according to Roman Jakobson’s rule of metaphor and metonymy. The masculinity and the femininity in Twombly’s series of Lepanto have a horizontal characteristic, different from Abstract Expressionism’s vertical dualism. Twombly’s series of Lepanto is included in the genre of a war painting, and like other war paintings, there are a large number of death in the series of Lepanto. Despite such a serious subject, however, sensuality exists in Twombly’s series of Lepanto. It is ascribed that extreme pain comes down to sensuality of death in the end. Life is a detour on the road to death and death is a process for life. pain and pleasure are one and the same. As a consequence, it can be deemed that the dualism in Twombly’s series of Lepanto is not for the confrontation, but for the union of opposites.