This study aims to examine the strength and force variability of lower extremity in adolescent Taekwondo (TKD) athletes according to different angular velocites and contraction types. Fifty-five youth male TKD athletes, aged 14-17 years old, participated in the study. Particiapants performed 5 times of isokinetic knee extension and flexion with concentric and eccentric contractions modes at three angular velocities (60, 120, and 240°·s-1). MATLAB code was applied to analyze peak torque (PT), torque variability (TV), and time to peak torque (TPT). A significant level was set at .05. Our results shows that eccentric contraction of PT, TV, and TPT were significantly higher than concentric contraction and the values decreased with the angular velocity increases (p<.001). Also, PT and TV and TPT were also significantly higher in the eccentric knee flexion and extension compared to concentric knee flextion and extension (p<.001). Eccentric contraction of PT, TV, and TPT were higher than conentric contraction in youth make TKD athletes. It is assumed that the risk of non-contact injuries may increase during eccentric contraction but future study is guaranteed to confirm the relations between eccentric contraction of PT, TV and non-contact injuries.