Depression is also known as depressive disorder， and the incidence is increasing year by year. The mechanism hypothesis mainly includes monoamine neurotransmitter hypothesis， monoamine receptor hypothesis， neuroendocrine hypothesis and brain-derived neurotrophic factor hypothesis. Nowadays， most depression models can simulate the behavior characteristics of patients with depression and the changes of neurotransmitters in the brain. In recent years， it has been found that the impact of gut microbiota on human body span the nervous， endocrine， immune and other systems and are related to the incidence of depression. The discovery of the relationship between depression and gut microbiota is helpful to provide a new way for the treatment of depression. In this paper， animal models of depression and related studies of gut microbiota are reviewed.