The present study aimed to examine the relationship between self-focus and rumination and that of self-focus and rumination to social anxiety and depression. Self-focus and rumination have been reported as cognitive features of social anxiety and depression. However,there is no evidence how these cognitive aspects affect on persistences or exaggerations of symptoms, and no discussion which cognitive factors affects on anxiety or depression dominantly. A total of 323 undergraduate students conpleted questionnaire. As result, social anxiety is linked with public self-consciousness and depression is linked with rumination. The results indicated that a core symptom of social anxiety is public self-consciousness and that of depression is rumination.