Abstract：To introduce the clinical experience of professor MA Lili treating psoriasis vulgaris. Professor MA Lili believes that heat，dampness and blood stasis are the key causes of psoriasis. In syndrome differentiation，it is necessary to combine the holistic syndrome differentiation with the local syndrome differentiation. In holistic syndrome differentiation，the attention should be paid to the changes of tongue and pulse； in local syndrome differentiation， the attention should be paid to the color，shape and location of rashes. In the treatment，it is advisable to treat the root and branch simultaneously，and caring for the foundation of acquired constitution of spleen and stomach should run through the entire course of disease treatment; the internal administration and external treatment are combined to achieve the best curative effect；Yinhua powder is made as the basic prescription of external treatment to be applied according to the mild， moderate and severe stages of the disease； emphasis is put on careful inspection， listening and smelling， inquiry and palpation as well as psychological counseling.