From the time of Neijing (Internal Classic) and Nanjing (Classic of Medical Problems) till the end of Qing dynasty, the medical scholars of each dynasty had taken the recognition of deqi as the subject in the stud- ies. Through the historical analysis, the content of regulating deqi was further understood in relevant ancient liter- ature. By checking the ancient works of acupuncture in each dynasty till the end of Qing dynasty, in reference to the evidences in over 10 works, such as Zhenjiu Dacheng (Great Compendium of Acupuncture and Moxibustion) , Zhenjing Zhinan (Instruction of Acupuncture Canon), Zhenjiu Daquan, and in association with the academic views of acupuncture masters in modern time, it was discovered that the medical scholars after the time of Neijing and Nanjing had enriched the understandings of deqi, such as the connection of cold and heat reaction, radiation to the affected site, reinforcing and reducing purpose in qi regulation. The methods of deqi regulations had, been explored till the end of Qing dynasty since the time of Neijing and Nanjing and the understandings of it were vari- ous among scholars.