Dermatomyositis is an autoimmune disease with complicated pathogenic factors. The present western medical treatment for it has severe toxic side effects, and thus Traditional Chinese Medicine(TCM)therapy is drawing increasingly attention. This paper analyzes and expounds the following issues as regard to its pathogenic factors and mechanism, pattern distribution, studies on the relativity of its patterns and biochemical indicators, treatment based on the combination of syndrome differentiation and disease diagnosis, and various TCM therapies.