This study was aimed to investigate the muscular functions such as peak torque, leg muscular endurance, ratio of muscular endurance, ratio of muscular strength, ratio of muscular deficit in left and right leg caused by extension and flexion at 60º /sec, 180º/ sec and 240º/ sec Cybex 340 exercise velocity, 10 male soccer palyer were selected out of the D University team. The results were as follows: 1. In maximal power efficiency, the mean torques of leg flexion were 138.0土20.20Nm, 104.4土14.07Nm, and 89.5土16.52Nm in left and 141.2土19.23Nm, 108.23Nm, and 88.6土14.43.Nm in right leg. The mean torques of leg extension were 154.9土26.49.Nm, 145.9土 18.24Nm and 111.4土17.41Nm in left leg and 150.2土33.71Nm, 143.6土20.78Nm, and 113.7土16.23Nm in right leg. And there was no significant difference between left and right leg. 2. The mean torques of total work in muscular endurance were 2246.80J and 2718.04J at flexion and extension respectively in the left leg and 2317.50J and 2659.10J at flexion and extension respect 96ively in right leg. there was no fignificant difference. 3.The ratio of muscular endurance in left leg were 60.7% at flexion and 52.3% at extension and in right leg were 56.1% at flexion and 47.2% at extension. There was sno significant difference. 4.The ratio of leg power(F/E ratio) at 60º /sec, 180º/ sec and 240º/ sec, the mean were 69.7%, 79.4% and 81.8%in left leg and 71.6%, 80.8%, and 83.2% in right leg. These calues were normal in view of common standard, but the values were abnormal in the view of elite plyer standard. 5. In deficit ratio of leg muscle at 60º /sec, 180º/ sec and 240º/ sec, the mean deficit ratio of results were-0.7%, -0.5% and -0.4% at flexion and 0.3% ,0.7% and -0.3% at extension. These calues were all normal. 6. In order to guide and upbringing the leg power of soccer player systematically, the analysis of leg peak torque, leg muscular endurance, muscle endurance ratio, muscular strength ratio and muscular deficit ratio using cybex dynamometer are thought to be neccessary. The trainer must utilize the profile based on this result into training. By this, the scienciric efforts to protect exercise injuries and to seek efficient rehabilitation from injuries and leg power strengthening or soccer player using cybex dynamimeter.