Abstract: HUANG Yuanyu summed up and established the unique theory of ascending and descending movement of middle qi from Zhouyi,Huangdi Neijing,Nanjing,Shanghan Lun,and Jingui yaolve. He holds that qi,yin and yang,five phases, and six climatic factors in the human body are all derived from the rotation of middle qi, and they are all in the ascending-descending rotation system with middle qi as the pivot. The normal operation of this system forms the physiology of the human body,and the abnormal operation leads to pathological changes. According to the understanding of six climatic factors of HUANG Yuanyu,it can be concluded that diseases of the human body are all related to six climatic factors which are not only associated with the pathological manifestations externally but also the changes of qi movement of the human body internally. Based on this medical theory,HUANG created the theory of nature of medicinals to adjust the abnormal qi transformation of the human body for treatments of diseases. HUANG also stressed that the wind and wood of six climatic factors are the pathogenic factors to the five viscera and the primary pathogen of all diseases. In addition,HUANG listed Radix Angelicae Sinensis as the top of Chinese medicine pertaining to wood in Changsha Yaojie. Therefore,the clinical application of Radix Angelicae Sinensis was discussed based on HUANG Yuanyu's theory of ascending and descending movement of middle qi;it is believed that Radix Angelicae Sinensis can not only treat diseases of wood qi,but also diseases of other four phases caused by wood qi,and this idea is well- embodied in Wenjing tang,Chixiaodou Danggui tang,Danggui powder, Danggui Beimu Kushen pills,Danggui Sini tang,and other prescriptions.