Abstract： Objective To investigate the incidence,sonographic appearance of the anatomic variation of carpal tunnel median nerve and its accompanying structures in healthy volunteers and explore the value of this variation in carpal tunnel syndrome.Methods A total of 360 hands of 180 healthy volunteers were included in the study.The full course of the median nerve in the forearm and carpal tunnel was examined with high-frequency ultrasound.The median nerve was first located in cross section at wrist and then with continuous cross-sectional scanning to observe the the full course of the median nerve in the forearm and carpal tunnel with high-frequency ultrasound.Results Anatomic variation of carpal tunnel median nerve and its accompanying structures were observed:① High division median nerve were found in 2 wrists (0.56 ％) ;②Bifid median nerve were found in 17 wrists (4.72％) ;③Persistent median artery were found in 22 wrists (6.11％),and 2 wrists (0.56％) were also found accompanied vein.Aanatomic variation of carpal tunnel median nerve accompanied with persistent median artery were observed in 16 wrists (4.44 ％).Conclusions High-frequency ultrasound was sensitive to diagnose the anatomic variation of carpal tunnel median nerve and its accompanying structures.Recognition of these variations can help us to make correct diagnosis of carpal tunnel syndrome.