Depression is one of the common psychiatry disorders， characterized by high prevalence， high disease burden，high recurrence rate， high disability rate and high suicide rate. Previous studies in China and other countrieshave found that depression patients have cognitive impairment of different degrees. Cognitive symptoms can occur earlier than other symptoms of depression， which is an important item in the diagnosis standard of depression， and also an important residual symptom， which seriously affects the life and work of patients. At present， the development of magnetic resonance imaging， nervous and biochemical detection， brain evoked potentials and other methods have assisted the research of cognitive function in depression. Among them， event-related potentials has become a hot topic of research. The review aims to summarize the development of event-related potentials in depression， which will provide an insight into the diagnosis and treatment of depression.