Abstract： Mr. REN Daran is one of the first mentors of the National Inheritance Class of Traditional Chinese Medicine Experts since the establishment of the People's Republic of China. He has been practicing Chinese medicine for more than 60 years，always adhered to the clinical frontline，learned from the ancient sages and the essence of medical books of all ages，and has been able to integrate them. He has unique originality in the differentiation and treatment of warm febrile disease. Mr. REN is skilled in treating warm febrile disease and carefully studies difficult miscellaneous syndromes. He advocates that the treatment for warm febrile disease should start with phlegm， heat and deficiency. He believes that the warm febrile disease are that the onset of the disease must be characterized by severe heat manifestations， with spreading pathogenic heat and rapid transmission and development. It is necessary to "treat disease before it arises" to stop the disease path，especially in the early stage of warm febrile seasonal disease；at the same time，it is important to take care of body fluids and stomach qi，correctly understand and flexibly apply the "sweat promotion" and "purgative method". If the disease is not treated properly or mistreated， the consequences will be unbearable，and if the treatment is appropriate，it will be effective soon.