Electrical vagus nerve stimulation (VNS) was approved by FDA for treatment of chronic recurrent depression in 2005. Recently, non-invasive, transcutaneous auricular vagus nerve stimulation （taVNS） has already been used for depression treatment. However, the neural mechanism remains unclear, and the relationship between stimulation parameters and neural response were also unknown. The present study aims to investigate the specific brain activation in depression patients after taVNS，compared with healthy controls.

Inclusion Criteria:

• Meets ICD-10 diagnosis standard;
• without taking anti-depressive medication or other psychiatric medications 2 weeks before the experiment;
• Patient has exhibited symptoms for at least 2 months, but no longer than 2 years.

Exclusion Criteria:

• With current addiction to drugs;
• With other severe organic diseases, such as severe heart disease, kidney failure etc;
• disagree with the consent form.
• Cannot receive MRI scan.