Background　Commonly used antidepressants have some defects including the delayed onset time of action and the low rate of effectiveness， whereas ketamine may exert a rapid and efficacious antidepressant effect.　Objective　This article reviews the clinical research advances in the antidepressant effect of ketamine.　Content　To summarize the antidepressant effects of ketamine in various depression and to elucidate the potential mechanisms of action and adverse reactions.　Trend　Further investigations regarding the antidepressant therapeutic protocol and the relevant mechanisms of action were needed on ketamine as a important new type of antidepressant.