In this study, the bibliographic classification, pathogeny, symptoms, therapeutics and prescriptions of Talyoung-Siljeong(脫營失精) were researched. Reference to consult about its origin and the process of development showed the following results. 1. It was 1117 that the difference between Talyoung-Siljeong(脫營失精) began to appear for the first time in classical literatures. 2. In view of psychological side, it is suitable for siljeong(失精), the part of Talyoung-Siljeong(脫營失精), to be called Taljeong(脫精). 3. Taljeong-Siljeong(脫營失精) was broken out by the internal factors. 4. Silyoung(失營) and Silyoung jeo(失營疽) are the worse states of Talyoung(脫營) and result in the incurable diseases. 5. Hypochondria and diaster psychology can be cured by the therapeutics of Talyoung-Siljeong(脫營失精). 6. Prescription for Heoro-Talyoung(虛勞脫營) can be used in cure of Talyoung(脫營). Talyoung-Siljeoung(脫營失精) remarked in traditional oriental meicine is recognized to belong to the part of stress in mordern medicine. It is thought that the experimental investigation should be continued.