Depression is one of the most common mental disorders in clinical practice， with unclear pathogenesis. The research shows that matrix metalloproteinases can be used as mediators to participate in the occurrence and development of depression by affecting neurons and their synapses， neurotransmitters， inflammatory response and epigenetics. In this paper， the research progress of matrix metalloproteinases in depression in recent years is reviewed， and the biomarkers and new therapeutic targets of depression are sought.