Comparison of Anyu Peibo With Placebo in Treatment of MDD，Ⅱb

Inclusion Criteria: * Adult with primary diagnosis of major depressive disorder(MDD) based on the criteria of DSM-5, single episode or recurrent episode. * The total score of MADRS is ≥24 in both screening visit and baseline visit. * The total score of HAMD-17 is ≥18 and the first item (depressed mood) is ≥2 in both screening visit and baseline visit. * CGI-S is ≥4 in both screening visit and baseline visit. * The subject understands and consents to takes part in this clinical trials. The subjects should sign informed consent form. Exclusion Criteria: * The subject has a suicide attempt within recent 1 year, or has a currently significant risk of suicide, or has a score ≥3 on item 3(suicide assessment) of the HAMD. * The subject has a current psychiatric diagnosis other than depression. * When the HAMD-17 score of baseline visit compares with the screening visit, the decreasing rate is ≥25%. * Known hypersensitivity to Big Leaf Ju, or at least to two kinds of drugs. * Any unstable cardiovascular, hepatic, renal, blood, endocrine, or other medical disease. * Any neurological disease (such as Parkinson's Disease, cerebrovascular accident and epilepsy) or cerebral injury (traumatic or disease related). * Had a history or a high risk related disease or medication of seizure disorder,except infantile febrile convulsion. * Had a history of hyperthyroidism or hypothyroidism within recent 1 year and still taking medication. * With psychotic symptoms. * The subject has a history of mania episode, including manic, mixed, bipolar depression or rapid cycle attack. * The subject has a current diagnosis of depression due to a somatic disease. * The subject could not take medication or has a disease affecting drug absorption, such as active bowel disease, partial or total intestinal obstruction, or chronic diarrhea. * Clinically significant electrocardiographic(ECG) abnormalities in screening visit. Such as QTc ≥450 ms in male or ≥470 ms in female; Sinus bradycardia and HR ≤ 50 bpm; Ⅲ atrioventricular block; atrial fibrillation, etc. * Clinically significant abnormal laboratory values(eg. Routine blood value above or below 1.2 times of the normal range; urine WBC, RBC or protein ≥++; ALT or AST value above 1.5 times of clinical top-limit; BUN value above 1.2 times of top-limit; Cr value above normal top-limit; thyroid gland function index above or below 1.2 times of the normal range, Fasting plasma glucose value above 1.2 times of normal top-limit; blood fat value above 1.5 times of normal top-limit). * The subject who used at least two different antidepressants with recommended dose and adequate duration (maximum dosage by at least 4 weeks according to label) treatment still had no respond. * The subject uses antidepressant drug normally before 2 weeks of screening, and stops using psychotropic drug before randomization less than 7 half-life period (monoamine oxidase inhibitor: at least 2 weeks; fluoxetine: at least 1 month) * The subject received light therapy within 2 weeks. * The subject received ECT, trans-cranial magnetic stimulation, or other physics therapy within 3 months. * The subject received systematic psychotherapy (interpersonal relationship, psychoanalytic therapy, or cognitive behavioral therapy) within 3 months or plan to use systematic psychotherapy during the study period. * The subject has a history of substance abuse (including alcohol, drug or other psychoactive substance) within 1 year before screening. * Women who were pregnant, breast-feeding, or serum-HCG(+) on screening; or planning to become pregnant within 3 months after kick-off of clinical trial. * The subject has participated in a drug clinical trial within 1 month before screening. * The investigator thinks the subject is unsuitable to enroll in this clinical trial.