Plotting out the meridian course with objective methods is one of the import- ant projects in the research of meridian at present

Therefore

selecting a proper indication to plot out the m(?)ridian track over the body surface during acupuncture is significant for elucidating the essence of meridian.The purpose of this paper was to plot out the Large Intestine Meridian track by blocking the acupuncture effect with mechanical pressure

when electroretinogram (ERG) was taken as a responsive indication.The plotting out the track was carried out on 5 subjects with marked propagated sensation along meridians (PSM) and 5 without PSM.The pressure was applied on Wenliu (LI 7)

Shou- shanli (LI 10)

Quchi (LI 11)

Binao (LI 11) and Jianyu (LI 15) respectively

when Hegu (LI 4) was punctured.Under such condition the variation of ERG amplitude decreased markedly or even disappeared.But the variation rate of ERG amplitude was still distinctly increased when the pressure was applied on both sides of any above points.The difference is highly significant (P<0.01). The results revealed that the meridian track over the body surface during acupuncture could be plotted out not only in the subjects with marked PSM

but also in those without PSM

when the proper objective indication was used. Its course basically coincided with that of the meridian described in the books of traditional Chinese medicine.Now it is safe to say the meridian track over the body surface is existed in human in common.It provides a new approach to plot out the meridian course with objective methods and opens up broad prospects for further application.