This paper explained the main manifestation of masked depression. Masked depression syndrome can be divided into “general cloak of depression syndrome”,“colorful cloak of depression syndrome”,and “weird cloak of depression syndrome”. Masked depression syndrome can be differentiated and diagnosed easily through the etiology,emotional manifestation,physique and natural endowment,personality features,mental disorders’ knowledge,the main points of four diagnosti  Methods:,as well as diagnostic treatment. The principle-method-recipe-medicines of depression syndrome has a big dispersion degree. The treatment based on syndrome differentiation should be flexible. We should pay attention on using the active placebo effect. We cure the disease can also help to dispel melancholy when the depression syndrome coexists with disease. Masked depression syndrome includes the somatoform disorders,autonomic dysfunction induced by recessive mental factors,and various kinds of physiological disorders. The pathogenesis of masked depression syndrome is related to inheritance,personality and psychological defense mechanism,cognitive ability,as well as alexithymia of the patients.