The paper deals with experiments in a young patient who suffered from nerve dea- fness. Whenever the propagated sensation along the Channels（PSG）reached the preau- ricular region

the patient heard a noise and an involuntary contraction of the muscles in that region appeared simultaneously. The properties of PSG were observed with EMG as an index to indicate the arrival or varia- tion of PSG

and the whole process of the blocking of activities of the Channels was re- corded objectively too.Furthermore by means of blocking of PSC a particular track over the"body surface"during acupuncture was mapped out for the first time. Its course coincided with the path of PSG and also app- roximately coincided with the Channel cou- rse described in the ancient medical books. Its existance was independant of the patient’s subjective will.It revealed that PSG was not a simple phenomenon of sensation but likely a reflection of a certain process actually pro- ceeding over the"body surface"during puncturel Results mentioned above presented some valuable data for the further investiga- tion of the mechanism of PSG and the elu- cidation of the essence of the Channels and collaterals as well.