The Seven-Branched Sword[Chiljido, 七支刀] was made in Baekje which was a kingdom founded in 18 BC in South Korea. The original sword has been conserved in the Isonokami Shrine[石上神宮] in Nara Prefecture. While there is a consensus that the appearance of the sword is basically similar to a shape of a tree, it is still controversial which types of a tree or plants the sword's unique shape was originated from. In particular, few literature has discussed the feature like the sword that three branch-like protrusions extending on each side of the sword's main body. This article focuses on a rice plant, named Dao(䆃), which has the peculiar shape with six leaves, Myung-hyeep[蓂莢], and six ears of the rice. The Myung-hyeep is known as a plant for counting a date or a month, and thus, six leaves of the Myung-hyeep refers to a year. The stem of it erected resembles the sword. The stems symbolizes a year or a pillar of the cosmos which connects the sky and the ground. If the Baekje sent the sword which was intended to symbolize the Myung-hyeep, it can be meant to bestow it to Japan. It is the Ilgyungreuksu [일경육수,一莖六穗] that a rice plant has six grains in a stem, called Dao. Its specific shape has yet known, but if it has three ears of each side of a stem like a letter 豐(feng) in a tile roof, it can be a similar shape with the Seven-Branched Sword. Given the shape of the Myung-hyeep symbolizing a calendar and that of the the Ilgyungreuksu like a ear of a rice, it is highly plausible that the sword can be used as a tool to display the authority of the king of Baekje for a ritual related to the sky or farming. In this article, we contrast the existing views of the period the sword was made, emphasizing on the seven-Branched Sword in Zinguki(「神功紀」) and Gilsangu(吉祥句) known as Byung-o(丙午) in May(五月) in Nonhyun(論衡). That is, according to ganji[干支] system in Japan, in case of that a specific date is engraved in a sword like Byung-o(丙午) in May 16th in the 4th year of Taewha[泰和], it is concurrent with a real date counted by the contemporary calendar. Especially, even though the date of Byung-o(丙午) existed in May in 369, no ancient books mentioned other dates the sword was made. Thus, when it is assumed the Byung-o(丙午) was in May in 369, the sword had been made in 362, or pressumed in November, the period can be suggested as in 408. Bakje took the Byung-o(丙午) in May(五月) in Nonhyun(論衡), but used 'full moon', Zhèngyáng(正陽), instead of 'middle of a day', Rìzhōng (日中), to show authority of the king of Baekje, indicating a gold dragon or meaning a phrase '南面受朝' that a king accepts a greeting of his Majesty's lieges sitting toward South. As the inscription, "Never before has there been such a blade", the Seven-Branched Sword expresses fully the creative and innovative culture of Baekje.