The bow and arrow played a very important role as an offensive weapon, as well as a hunting tool, in the Three Kingdoms period. However, only arrowheads are extant due to the material properties of the other components of the bow and arrow. Among the weapons of the Three Kingdoms period, arrowheads represent the most numerous find. Previous studies have focused only on the analysis of narrow arrowheads. However, it is highly probable that wide arrowheads, which have widely and steadily been identified in the archaeological record, were also responsible for important functions, even though excavated examples have been more limited in number, compared to narrow arrowheads. As such, it is difficult to discuss the operation of bows and arrows without a review of wide arrowheads. Research was therefore undertaken with the view that the changing aspects of wide arrowheads can provide an important means of reconstructing the operation of bows and arrows. Changes in the operation of bows and arrows can be examined through four stages. The first stage, dating from the end of the 3rd century to the first half of the 4th century, is characterized by the marked division of arrowheads. Bows and arrows appear to have been used in hunting and warfare. Shots were usually aimed from a short-distance in this period. In the second stage, dating from the second half of the 4th century to the first half of the 5th century, it is likely that bows and arrows were mostly used in warfare, and shots were aimed from both short and long distances. The third stage, dating from the middle to late 5th century, witnessed the most significant change that took place in relation to the operation of the bow and arrow in the Three Kingdoms period. Bows and arrows were mainly used in warfare. There were various ways of operating the bow and arrow. Shots could be aimed from both short and long distances, and unaimed shots could also be fired. Shots aimed from a shortdistance by archers on horseback were utilized in hunting, training, and battles. The fourth stage dates from the first half of the 6th century to the unification of the Three Kingdoms. Little difference could be identified between the third and fourth stages in terms of the operation of bows and arrows. However, it can be surmised, based on the appearance of the f-type arrowhead and the way in which arrowheads became longer and harder, that the military system gradually came to be fully established around this time and that the penetration and flying distance of arrows greatly increased.