The purpose of this study was to investigate the balance differences between skilled players and less-skilled players during Hakdariseogi motion of Keumgang Poomsae in Taekwondo. To achieve the study goal, total of 10 Taekwondo athletes; 5 skilled players(S, body mass: 67.0±5.7 kg, height: 174.0±4.8 cm, age: 20.0±2.0 yrs) and 5 less-skilled players (LS, body mass: 73.0±4.9 kg, height: 176.4±6.1 cm, age: 20.8±1.3 yrs) participated in this study, A three-dimensional motion analysis with 8 infrared cameras and one force plate whose sampling frequency as 30 Hz and 300 Hz, respectively, were performed, Participants` motion were divided into three phases which were preparation phase (P1), performing phase (P2) and maintaining phase (P3). The range and velocities of COP, the range and RMS of ground reaction torque and displacement between COM and center of BOS of each phase were computed. In this study, at P1 and P3 which were double and single stance, respectively, the range and M-L velocities of COP revealed significantly higher in LS compared with those of S(p<.05). At P2 which was single stance, LS indicated significantly higher in range of COP and ground reaction torque, and M-L velocities of COP than those of S (p<.05). The significantly shorter displacement between COM and center of BOS, however, was found in LS compared with that of S (p<.05). The results from our study indicated that S revealed more stable performance and a better posture control ability during performing Hakdariseogi motion.