This primary purpose of this study is to assess the efficacy and safety of Effexor XR in preventing recurrence in Chinese patients with recurrent major depressive disorder (MDD) following a 1-year maintenance treatment after an 8-week acute treatment and a 6-month continuation treatment phases. The study will also collect data on the prevalence and pattern of co-morbid anxiety and somatic symptoms and their impact on the recurrence of depression.

Inclusion criteria: 1. Males or females, 18 years of age or more; 2. Outpatients; 3. Major depressive disorder based on DSM-IV criteria, with/without current co-morbid anxiety disorder; 4. Has two or more episodes of depression (including the current episode) in the past 5 years, with an interval of at lease 2 months between the end of the previous episode and the beginning of the current episode. 5. The baseline score of 17-item Hamilton Rating Scale for Depression (HAM-D)>=17; 6 If female of childbearing potential, have a negative urine pregnancy test at baseline, if appropriate, and use a medically acceptable method of contraception throughout the study.

Exclusion criteria:1.Hypersensitivity to venlafaxine;2.Received venlafaxine treatment before;3.Clinically significant renal or hepatic disease or any other medical disease that, in the opinion of the investigator, might compromise the study, including seizure disorder (with the exception of a single childhood febrile seizure); 4.Alcohol or drug abuse within the last year;5.A recent history of myocardial infarction or unstable heart disease (within 6 months of baseline);6.Bipolar disorder;7.For female, known or suspected pregnancy or breast feeding;8.Use of a monoamine oxidize inhibitor (MAOI) within 14 days of baseline; use of any investigational drug within 30 days of baseline.