Major Depression Disorder is one of the most common psychiatric disease and has affecting approximately 350 million people in the world. According to World Health Organization's report, it may be the first burden of disease in 2030. Due to the high morbidity and low acceptance in the treatment, it is necessary to find some nature compounds to prevent the disease.

Cordyceps militaris, one of the most treasure Chinese herbs in Asia, contains many kinds of component such as cordycepin, polysaccharide, mannitol. In winter, it appears as an worm in the soil, afterwards, it grows out of the soil and convert into grass in summer. A previous study has demonstrated that Cordyceps militaris has anti-depressive effect in mouse tail suspension test, and in this study we will explore its effect in human subjects.

Inclusion Criteria:

1. 21 -items Hamilton Rating Scale for Depression scores 8-17 points upon interview
2. At least 2 weeks not taking antidepressants, antipsychotics or antiepileptics.
3. Understand the whole process of the study and had signed the informed consent form

Exclusion Criteria:

1. Had been diagnosed with severe mental disorder, schizophrenia, bipolar disorder, personality disorder, substance use disorder or alcohol use disorder, or other severe physical illness that is not expected to survive during the intervention period.
2. Currently taking antidepressants or other medication that may impact the study.
3. Expected to be non-adherent.
4. Without sufficient data to confirm safety.
5. Pregnant woman
6. Allergic to fungal products.
7. Currently taking MAO-inhibitors

The study has not yet fully discuss the plan for IPD opening.