The study is to investigate the non-inferior efficacy of Paroxetine Controlled Release to Paroxetine Immediate Release, as well as the drug tolerability profile when treated on patients with Major Depression.

• Drug: Paroxetine CR
• Drug: Paroxetine IR

Inclusion Criteria:

• Patients with Major Depressive Disorder,score on depression rating scale reach a specific point(17 item Hamilton Depression Scale>18).

Exclusion criteria:

• patients use monoamine oxidase inhibitors (MAOIs), benzodiazepines, Chinese herbal medicines, acupuncture, moxibustion or other psychoactive medications other than zolpidem, zopiclone;diagnosed with other Axis I disorder other; not responsive to paroxetine therapy before; pregnant or lactating, have serious medical disorder or condition that would preclude the administration of paroxetine; have a history of seizure disorders (except for febrile seizures in childhood); require treatment with warfarin anticoagulants, phenytoin, cimetidine, sumatriptan, type 1C antiarrhythmics, quinidine or sulfonylurea derivatives; are substance abuse or dependence (alcohol or drugs) within 6 months prior to this trial; have had electroconvulsive therapy within 2 months of entry into the study; pose a current, serious suicidal or homicidal risk; have taken other psychotropic drugs or antidepressants other than MAO inhibitors within 7 days of baseline and MAO inhibitors within 14 days of baseline; have taken any investigational drug, or participated in a clinical trial within the past 3 months; are hypersensitivity to paroxetine; have undergoing formal psychotherapy/psychoanalysis.