Abstract: Identification of complex traumatic stress disorders has beyond the traditional definition of trauma and experimentally diagnostic statement of post-traumatic stress disorder (PTSD) in Diagnostic and Statistical Manual of Mental Disorders (DSM-Ⅳ-TR). Because of the disturbance of complex trauma, traumatic stress symptoms and its hurt results, it is difficult to make accurate diagnosis and effective treatment. This article began with the reasons why it was hard to define complex trauma, viewed from clinical diagnosis and treatment, discussed the importance of defining complex trauma, its multiple effects on individuals and the psychological and social factors aggravating complex trauma.

Key words: complex trauma, definition, multiple effects, review