Since Hughes separated the polypeptide with morphinelike activity from pig's brain in 1975

the re-search of the endogenous morphine like substances has made great progress. It is obvious that the subs-tances having various structures and their receptors (opiate receptors) can be divided into several subtypes.The substances exist in many tissues and organs and are widely connected with the functions of C. N. S.and endocrines. Therefore

they play an important role in physiology and pathology. Now the substanceshave become a new subject of research in numerous scientific fields as well as acupuncture analgesia. This paper gives a general statement about the recent research of the substances is designation

classification

structure speciallty

distribution and location and their receptors. Mainly discussed arethe physiological function of these substances as neurotransmitters in transmission of central impulses

regulating the sensation of pain

participating in stress reaction and addiction

and influencing theactivity of endocrines and neuropsychomotors

etc. In addition

the endogenous morphine-like substancesmay be regarded as an actual material foundation in acupuncture analgesia.