The concept of

deqi

in acupuncture was first documented in

Huangdi Neijing

(

The Yellow Emperor's Inner Classics

). It is one of the most fundamental concepts in the theory of acupuncture techniques and serves as a representative term for describing acupuncture effect. The relevant judgement and description of it primarily rely on subjective perception and experiences. The response to acupuncture stimulation in the body and its influencing factors are highly complex. Although acupuncture practitioners throughout history have all recognized t

heir importance

their understanding remains inconsistent

leading to inevitable conceptual ambiguity. Based on theoretical analysis of ancient literature

this article argues that the concept of

deqi

discussed in the acupuncture-related sections of

Huangdi Neijing

has not yet been formalized into a standardized term. The connotation of

deqi

has undergone significant transformation

evolving from the "result" of reinforcing-reducing technique to its "premise". The understanding of

deqi

initiates the development of reinforcing-reducing technique

from "

qi

communicating with heaven and earth" to "

qi

beneath needle". The article proposes: understanding

deqi

should consider the overall reaction of acupuncture and its historical context

elucidating its essential characteristics and practical significance is one of the key issues in constructing the contemporary theoretical framework of acupuncture and preserving its empirical knowledge

and determining

deqi

and acupuncture efficacy by pulse diagnosis still retain their clinical practical value.