Neo-Confucianism was the dominant ideology of the Joseon Dynasty Korea. Male and female costumes reflected a clear distinction in male and female sex roles. This study analyzes cross-dressing in sword dance performances. The research method examines relics, paintings, pictures, and documents relevant to sword dance costumes as well as for the military. The results are: First, the composition of sword dance costume was jeogori (upper garment), skirt, and shoes with military costume of jeollip (hat), jeonbok (long vest), and jeondae (belt). Second, the sword dance costume and military costume are very similar except for the basic inner wear, shoes, some details and methods of wearing. Third, the sword dance costume gradually adopted military items and features. The sword dance costume was basically female, with overall additions of a male costume, to express an androgynous image; however, the cross-dressing phenomena in the sword dance were not intended for the pursuit of sexual pleasure.