Sub-threshold depression belongs to psychological sub-health phenomenon,which is usually depressive-mood based.In contrast to the depression,sub-threshold depression is in the absence of a recognized clinical identification tool.In psychological counseling and clinical diagnosis,the physician often needs to screen patients with sub-threshold depression with depression rating scale for depression.But in the practical application,the evaluation exists irrationality and limitations.From the aspects of the definition of sub-threshold depression,the understanding of Chinese traditional medicine for the disease and its symptom identification,the paper analyses the advantages and disadvantages of the current depression scale of assessing sub-threshold depression,and provides theoretical references for establishing the identification and selection system of sub-threshold depression.