Objective To investigate the biomechanical properties of the posterior tibial anatomic plate. Methods A total of 25 fresh frozen adult tibial top and matching femur specimens were randomly divided into four groups. One specimen was used as normal control ( N group), and the remaining 24specimens were with Schatzker Ⅵ tibial plateau fracture and accompanied by rear split and backward fracture displacement. The lateral margin of the tibia was fixed with a L-type plate, and the medial margin was fixed with the same plate after remodeling. The 24 specimens were divided into three groups, eight specimens per group. The posterior margin of the tibia was fixed by posterior tibial anatomic plate ( Group A), T-type plate ( Group B) or straight reconstruction plate ( Group C). The strength, stiffness, torsional biomechanics and failure load performance of the plates in each group were evaluated. Results The strength and stiffness of test groups was superior to that of Group N ( P ＞ 0.05 ), and the torsional biomechanics of test groups was close to that of Group N ( P ＞ 0.05 ). The posterior tibial anatomic plate was superior to T-type plate and straight reconstruction plate in aspects of strength, stiffness, torsional biomechanics and failure load performance ( P ＜ 0.05 ). Conclusions Posterior tibial anatomic plate has excellent biomechanical properties, and it is superior to other materials in treating posterior tibial plateau fracture and restoring the stability of the knee.