The study compared to skills of Yeopchagi and Dolyeochagi in Taekwondo with the 3d kinematic analysis. To compare both of two skills, the study was analyzed as the relative time during the skills performed, the kinematic characteristics of individual segment, the relationship of inter-segment and the ranges of motion in 3d space. A performance time was mort shortened Dolyeochagi than Yeopchagi. A relative time that the time minimized angle of shank was later Dolyeochagi than Yeopchagi. The characteristic of kinematic of Individual segments showed clearly different in the flexion/extension plane. The angle of thigh increased continuously at an impact in Yeopchagi, but the angle stopped or decreased in Dolyeochagi at that time. The relationship of inter-segment showed difference largely between two skills in the flexion/extension plane, but the other plane showed no difference. These results were due to anatomical functional difference between two joints. The ranges of motion in 3d space were different at the abduction/adduction and the internal/external rotation.