With the use of computer image processing technology , a new method was proposed for studying the contact characteristics of the subtalar joint. The results showed the total subtalar articulation area was 9.52±0.40 cm2. On neutral position and under 600N load, the contact area of the subtalar joint was 2.00±0.11cm2. The contact area of the posterior articulation was significantly larger than that of the anterior and medial articulation (p<0.01). The average contact pressure was 19.3±1.38N, the force transmitted by the subtalar was 389.16±28.75N, which accounted for about 64.86% of the applied shank load(600N), and 69.39% of the force was transmitted by the posterior articulation. The posterior articulation plays an important role in the load. The fracture line of the calcaneus often appears in this area.