Objective To explore the accurate position for the intersect between the short axis of the tibial tray and patellar ligament through studying the relationship among the femoral epicondylar(FE) axis, posterior femoral(PF) axis, posterior tibial(PT) axis, patellar(PAT) axis and patellar ligament(PL). Methods Magnetic resonance imaging (MRI) scans of 40 knees are included in this study. Using the computer workstation, these axial scans were used to construct the FE axis,PF axis, PT axis, PAT axis and PL. Angles between the axes of the selected landmarks were calculated, and linear regressions were performed to assess the relationship between the axes. Template of the tibial tray were positioned along both the FE axis and PT axis and the resultant points of patellar ligament intersection were recorded, and the difference of the intersect was analyzed with the matched t test. Results Strong relationship were found between the FE and PAT axes(1.8?? 3.6?, R2=0.70), as well as between the FE and PF axes(6.1?? 3.0?, R2=0.79). When the tibial template was aligned along the FE axis, 65% of the cases were in an ideal position, and the intersect is at the 10%-60% width of the patellar tendon. When the PT axis was used, 35% were optimal, and the intersect is at the -15%-35% of the width. And the difference in the mean value of the intersect is of statistical significance. Conclusion During total knee arthroplasty, if the short axis of the tibial tray is aligned with the intersects of the PL between its midpoint of the medial third to a half of its entire width, the rotation of the tibial component will fit the FE and PAT axes closely, so the component's position is appropriate.