Objective To introduce a 4 quadrant zoning method measuring dynamic force distribution of multi-bundle fibers in anterior cruciate ligament (ACL) to find out the mechanical relationship between tibial footprint and force distribution of ACL multi-bundle fibers. Methods A cadaveric study was performed with 8 normal Chinese human knees. After the integrity evaluation of each specimen d, the tibial insertion site of ACL was detached from plateau through a tibial tunnel. The footprint was averagely separated into 4 zones according to sagittal plane and coronal plane as zone 1 (posteromedial zone), zone 2 (posterolateral zone), zone 3 (anterolateral zone) and zone 4 (anteromedial zone). Fibers were also separated into 4 bundles according to each attached zone and linked to the custom-made force transducers. Zero strain was set to all bundles at 90o and 0o respectively and forces of each bundle were measured during 0-120o of knee cyclic motion in four degree of freedom (DOF) of knee joint during flexion and extension. Results The forces measured from zone 2 and 3 increased during extension. The max force of zone 2 reached 22.52±8.60N (30o) and thatof zone 3 reached 13.98±3.47N (0o). Forces of zone 3 and 4 increased during flexion. The max force of zone 3 was 9.84±5.06N (60o) and that of zone 4 was 14.68±5.29N (90o). Forces in all fibers increased during the valgus, rotation and anterior drawer tests. Force distribution in zone 1 did not change in most DOF of knee. Conclusion The fibers attached to the posterolateral zone contributes to the largest restraint of anterior tibial translation. While the anteromedial zone plays the most important role during knee flexion. The anterolateral zone contains the fibers functioning as linkage during flexion and extension, so it can be regarded as the transient fiber of ACL during movement. In this study, we found that 4 quadrant zoning method of ACL tibial footprint helps to learn the continuous dynamic force distribution of ACL multi- bundle fibers, and provide the basic parameters for further study.