Objective To provide anatomical basis for the treatment of sinus tarsi syndrome by developing the anatomical structure of sinus tarsi.  Methods Thirty formalin fixed lower limb specimens were dissected. The anatomic structures of the sinus tarsi, neurovascular tissue, ligament and adipose tissue were observed and measured. Morphologies of the sinus tarsi and canal of tarsus in intact dry calcaneus and talus of 136 Chinese adult specimens were investigated and measured.  Results The artery of the sinus tarsi and its periphery issued from the dorsalis pedis artery, anterior medial malleolar artery, perforating peroneal artery and lateral tarsal artery. The laterosuperior point of cuboidal articular surface of calcaneus was the obvious osseous marks of the lateral surface of sinus tarsi. The length canal of tarsus, sinus tarsi  and the calcaneal sulcus were (14.85±2.08)(8.33-22.00)mm, (26.38±3.05) (16.54-35.79)mm and (41.25±3.52)(31.06-53.92)mm respectively. There was a angle between two axes of calcaneus and tarsal canal, which was (49.37±4.76)(39.18-56.37)°. Conclusion During the treatment of sinus tarsi syndrome by the local steroid injection, the laterosuperior point of cuboidal articular surface of calcaneus should be palpated firstly, which is the point of inserting the needle. Then, the injection needle is towards posteromedial at 49°, and advance 2.5 mm to touch the sinus tarsi.