Objective: To observe the value of transcranial sonography (TCS) on diagnosis of Parkinson disease (PD). Methods: Totally 478 patients (disease group) clinically diagnosed as neurodegenerative diseases were stratified as PD, Parkinsonism-plus syndromes, secondary parkinsonism and essential tremor subgroups. In addition, 124 normal volunteer were selected as control group. All subjects underwent TCS to obtain the area of substantia nigra (SN) hyperechoes. The positive rate and area of SN hyperechoes were compared among the groups. The sensitivity and specificity of area of SN hyperechoes for diagnosing PD was calculated, respectively. Dopaminergic responsiveness test was performed in PD patients, and the positive rate of Dopaminergic responsiveness test was compared with the rate of SN hyperechoes. Results: The display rate of midbrain in TCS was 81.72% (492/602). After rejecting subjects with unclear images, there were 389 in disease group (including 170 PD cases) and 103 in control group. The rate and area of SN hyperechoes in PD subgroup were both higher than those in the other groups. The diagnostic sensitivity and specificity of SN hyperechoes was 81.76% (139/170) and 77.64% (250/322), respectively. There was no statistical difference between positive rate of SN hyperechoes and dopamine response in PD subgroup (P>0.01). Conclusion: SN hyperechoes was a characteristic manifestation on TCS in patients with PD, having important clinical application value. Copyright © 2013 by the Press of Chinese Journal of Medical Imaging Technology.