By making anterior and posterior drawer tests using "Laxity tester" is an objective way to evaluate the resting position of tibia plateau and knee laxity. This study followed up 16 cases of PCL reconstructed or pull-out repaired knees for an average of two years and seven months. A force of 20 1b was applied to evaluate knee laxity at 30 degree and 90 degree knee flexion. From paired t-test, the stability of reconstructed knees was not statistically different from that of control contralateral normal knees. The functional scores measured by the Gillquist scoring system for injured knees after reconstruction were satisfactory. Therefore the restabilized PCL deficient knees by the modified Clancy method or pull-out repair yielded good evaluation scores. The data of contralateral normal knee laxity obtained in this study was used as reference in pre-operative and post-operative evaluation of PCL injured knee.