Objective　This study aims to provide an anatomic basis for surgeries accompanied with the pudendal nerve and some explanations about the formation of thepudendal nerve.　Methods　The pudendal nerve was dissected from its origin to end branches in 16 human cadavers. Its formation, shape, tract, branches and relationship with vessels were observed. The data related to the pudendal nerve were also measured.　Results　The formation of pudendal nerve is discrepant from what we acknowledged before. The trunk of pudendal nerve is formed by the anterior branches of S2, S3 and S4 with S4 being absent in some cases. In the descending course, the trunk of the pudendal nerve is combined with some fibers from the posterior femoral cutaneous nerve and the sciatic nerve in its course. The intricate shape of the pudendal nerve owes to its relation with the posterior femoral cutaneous nerve and the sciatic nerve, and the relations among its branches also contribute to that. The relationship with vessels varies during its course in the inferior border of piriformis and the pudendal canal. The branches of the pudendal are divided into the branches in the pelvis and the branches out of the pelvis. The distance from the pudendal nerve in the Alcock’s canal to the bottom of the ischial tuberosity’s anterior border is (25.47±3.18) mm in male and (26.38±2.56) mm in female. The distance from the pudendal nerve at the ischial spine to the skin is (75.67±8.37) mm in male and (76.89±9.48) mm in female.　Conclusion　The detailed dissection of the pudendal nerve can guide clinician in the surgeries associated with pudendal nerve in some degree.