There are many postoperatve evaluation methods of knee ligament injuries and different results can be made according to different evaluation methods. But, it will be helpful to lessen the bias between different methods using objective muscle power evaluation. We conducted a clinical study on 20 patients (16 males and 4 famales) of knee ligament injuries from April 1990 to September 1991 in Asan Medical Center. Two knee scoring scales (visual analog scale by Flandry et al. and knee score by Lysholm and Gillquist) were used in comparison with Cybex 340 isokinetic dynamometer evaluation. We analyzed the differences between them. The results were as follows; l. A great interpersonal variation of the hamstring-quadriceps ratios was noticed not only in the injured knees but also even in the uninjured knees. 2. Significant decrease of peak torque appeared in quadriceps in injured knee joint. 3. Hamstring-quadriceps ratio differences between both knees did not correlate with visual analog scale and Lysholm knee score and vice versa.