The purpose of this study was to identify aspects of Koryo poomsae that affect judges` decisions in order to quantify a more accurate scoring system in Taekwondo poomsae competition. Twenty male Taekwondo poomsae athletes aged 18-20 yr participated in this study. Subjects were divided randomly into two equally-sized groups (Group A and B). All participants performed Koryo poomsae twice, and the best performance was used for analysis. The poomsae performance was evaluated by 5 judges, then the average score was calculated without the highest and lowest scores. Kinematic variables included performed time, center of mass (CM) range, kick height, and stance length of four phases in Koryo poomsae. The results showed that a significant difference was obtained for the time required between Phases 3 and 4 in Group A. There was a significant difference for the ratio of yopchagi (Taekwondo side kick) height to body height between Phases 3 and 4 in Group A. Angle change of knee joint during yopchagi was significantly different between Phases 3 and 4 in Group A. However, no difference was found for CM range and stance length between the groups. The results of this study suggest that kinematic parameters such as the time required, ratio of yopchagi height relative to body height, and the angle change of the knee joint should be considered significant indicators to establish a more accurate scoring system for Koryo poomsae competition.