Objective　To provide anatomic basis for treating the isolated posterolateral fractures of the tibial plateau by posterolateral approach.　Methods　(1) The main vessels, nerves, muscles and ligaments relative to the posterolateral approach were observed and measured on 20 lower limbs of adult cadavers. (2) To make sure the practicality of the posterolateral approach, surgical simulations were performed on another 4 lower limbs of fresh adult cadavers. (3) The approach was clinically applied on 12 cases. The clinical characteristics and the treatment outcome were also analyzed.　Results　The operative incision of this approach can avoid to reach the common peroneal nerve trunk. The vascular nerve bundles were protected when the deep dissections were carried on in the intermuscular septum between the lateral side of lateral gastrocnemius muscle and the soleus muscle. The distal dissection should be restricted no more than (4.15±0.36) cm below the fibular head level, as the anterior tibial vessel passed through the interosseous membrane, and the space is enough for the reduction and fixation. Satisfied results were obtained in all 12 cases adopting this approach.　Conclusions　The posterolateral approach is an ideal way for the treatment of isolated posterolateral fractures of the tibial plateau. The advantages of this approach are as follows: the exposure is good and safe, the injury is limited and the clinical results are excellent, and it's with certain value for popularization.