Abstract: "Syndrome", "symptom" and "sign" were basic and core conceptions in traditional Chinese medicine (TCM) while there was no definite interpretation of syndrome in the field of modern TCM, which generally tended to interpret it from the perspective of modern application. There was no dynamic and three-dimensional combing on its origin and development, especially for radically different understanding of "sign". The paper combed exemplifications in significant TCM classics, which was proved by the change of literal meaning of "symptom" and "sign". It explored the original usage and derivation change of "symptom" and "sign" from the perspective of dynamic change, thus the basic meaning of "syndrome" could be interpreted. "Symptom" referred to diseases pattern, including individual pattern or symptom clusters. "Sign" referred to the external subtle characteristics which could manifest personal health or disease situation and provide guidance for doctors to identify physical and disease condition. "Syndrome" was the combination of "symptom" and "sign".