Abstract： Elderly patients with external cold cough are prone to cold pathogenic factors due to deficiency of the body.The in-itial pathogenic factors are on the exterior,but the disease is prone to transmission and transformation.If treated incorrectly,it can quickly enter the interior and cause complications.Modern medicine cannot fundamentally reduce the cough sensitivity of the eld-erly cough patients.Treatise on Febrile Diseases makes the disease differentiation according to six meridians.Combining with the eight principles of syndrome differentiation,modern doctors have proposed that Shaoyin disease is the exterior Yin syndrome,focu-sing on the root deficiency and the external wind and cold reflecting on the exterior,and treating it fundamentally.Professor LYU Xiaodong is skilled in treating external cold cough in the early stages of the elderly patients based on syndrome differentiation,which is in line with the characteristics of the elderly patients'deficiency constitution and the pathogenesis of cold pathogenic fac-tors.Its characteristic is to focus on warming and tonifying,rather than attacking and resolving external pathogenic factors.Based on one clinical case,it hopes to provide some clinical ideas for the precise treatment,research and prevention prognosis of the eld-erly patients with external cold cough.