Abstract:【Objective】 To investigate the anatomic sites to locate the center of reconstruction of the anterior cruciate ligament in knee flexion angle ligament length and its significance. 【Methods】 From 2011 August to 2012 June 35 cases patients with cruciate ligament injury before arthroscopic reconstruction of the anterior cruciate ligament, ligament femoral attachment point center anatomical attachment dot center in the knee joint of 0°, 30°, 90°, 120° multi flexion angle when the length of the tibia were measured on the cross, and to understand its relationship with height. 【Results】 The anatomic center positioning of anterior cruciate ligament reconstruction with unequal, anterior cruciate ligament knee flexion 0° length and bend 30°, 90°, 120° had significant difference, while flexion 30°, 90°, 120° ligament length no statistical difference between them. Length of anterior cruciate ligament of knee at 0° is (26.1±4.8) mm. With the flexion 30°, 90°, 120° ligament length was (23.9±4.5) mm (=0.05, P <0.001). At 0° length was longer than 30°, 90°, 120° of ligament length was about 2.2 mm. The anatomical location of anterior cruciate ligament reconstruction with height, the linear regression equation for anterior cruciate ligament length (Y) and height (X) of the relationship: Y=-4.1097+0.039X (α =0.05, P <0.001). 【Conclusion】 Anterior cruciate ligament reattachment point center positioning reconstruction of knee flexion angle ligaments unequal, ligament is strained knee extension, slightly relaxed down, there is no significant difference between flexion angle ligament length, length and height are related, considering the ligament reconstruction positioning and fixing time.