SUMMARY:To reveal the detailed morphological features of the fibular collateral (fibular) ligament, popliteus tendon, popliteofibular ligament and the synovial components regarding to achieve data for surgical and biomechanical utilization. Knees of 10 formalin-fixed male cadavers were dissected bilaterally. Bursae around the lateral collateral ligament and the relation of popliteus tendon with lateral collateral ligament at the femoral attachment site were noted. The positional relation between both ends of popliteofibular ligament was evaluated statistically. The PT exceeded the anterior margin of lateral collateral ligament in 11 sides, the posterior margin of lateral collateral ligament in 3 sides and exceeded both the anterior and posterior margins of lateral collateral ligament in 5 sides. The shape of lateral collateral ligament was narrower at the lower part than the upper in 14 sides. The width of lower part of lateral collateral ligament was found narrower in the cases with sheath-like bursa (vagina synovialis). The relation between both ends of popliteofibular ligament was as followed: the more anteriorly the fibular head attachment was located, the more anteriorly popliteofibular ligament was attached to the popliteus tendon. To resolve the posterolateral corner of the knee with regard to surgical anatomy and biomechanics, individual and concerted morphometric characteristics of lateral collateral ligament, popliteus tendon and PF should be evaluated together with accompanied synovial structures.