Abstract：This paper introduces the experience of Professor GAO Ya in treating mesenteric lymphadenitis in children from phlegm. Professor GAO Ya believes that “phlegm pathogen” is an originating factor that induces and aggravates mesenteric lymphadenitis and runs through the whole disease. Phlegm is the root cause of the disease and “phlegm node” is a pathological product，and therefore fortifying the spleen and resolving phlegm，conditioning qi movement as well as moving qi and alleviating pain should be applied in the clinical treatment of mesenteric lymphadenitis in children. The Jianpi Huatan Zhitong prescription is created for syndrome differentiation and treatment，which has a good curative effect.