Objective To investigate effectiveness of applying the Bone Morphingbased image-free computer-assisted system for the ligament balancing managementin the total knee arthroplasty (TKA). Methods Between November 2002 and June 2003, twenty-one posterior stabilized total knee prostheses (Ceraver, France) were implanted in 21 patients using the Bone Morphing based image-free Ceravision system.This cohort included 5 men and 16 women with an average age of 72.4 years, two undergoing high tibial osteotomy and 1 undergoing distal femoral osteotomy before. The preoperative deviation was measured by the full-length AP X-rays. The knees were in varus deviation in 14 patients and in valgus deviation in 7 patients, with an average of 2.36°(varus 13°-valgus 13°). The frontal X-rays ofthe knee were assessed, the mean value of the varus force-stress test was 8.47°(varus 2°-varus 20°), and the mean value of the valgus forcestress test was 3.63°(varus 7°-valgus 12°). Results With the Ceravisionrecorded data, the intraoperative alignment was assessed, the mean lower limb axis was 3.33°(varus 12°-valgus 10°),and compared with the preoperative data, the difference was significant (Plt;0.05); the mean value of the varus force-stress test was 6.47°(varus 0°-varus 24°), the mean value of the valgus force-stress test was 4.32°(varus 8°- valgus 15°), and compared with the preoperative data, the difference was significant (Plt;0.05). The post-prosthetic alignment on Ceravision with a deviation of 0.175°(varus 2°- valgus 3°) was compared with the postoperative alignment by the full-length AP X-rays, with a deviation of 0.3°(varus 3.5°-valgus 1.5°), the difference wasn’t significant(Pgt;0.05).The clinical check-up performed 3 months after operation showed that the average range of movement (ROM) was 115°(105-130°), the mean frontal laxity was 0.27 mm(0.2-0.5 mm). The femoral and tibial components were implanted in the satisfactory 3 dimensional position without ligament imbalance in all the patients, andthere were no instability or patella complications.Conclusion Utilization of the Bone Morphing based image-free computer-assisted system can achieve an accurate component 3 dimensional alignment, optimal bone resection, optimal control of surgical decision in releasing the soft tissues, rotating the femoral component to gain an extension/flexion rectangular gap, and managing theligament balancing so as to achieve a satisfactory initial clinical outcome. This system can be routinely used in the TKA.