Abstract：Professor OUYANG Weiquan's treatment for atopic dermatitis with classical prescriptions mainly relates to the following aspects：differentiate six meridians first to determine the direction，and differentiating prescriptions and syndromes next is the tip； pay attention to the view of holistic syndrome differentiation， and see through the rashes to perceive the essence； attach great importance to formula- syndrome differentiation and constitutional identification， and expand the treatment of dermatosis by classic prescriptions； use medicines flexibly and take more thinking， and the combination of internal and external treatment quickly takes effect. In the process of syndrome differentiation and treatment, it is emphasized to recognize the pathogenesis of every disease and to expand the subject range of classic prescriptions by grasping the pathogenesis behind the prescriptions and signs.