The so-called modernization in the preparatory process of oriental medical herbs invites two medical hazards: namely, falsification or fake on the one hand and misuse of one extract for another on the other hand. The identification of the effective compound with physico-chemical means thus becomes necessary burden. In an effort to find out a cheap yet dependable method to distinguish the extracts of Panax ginseng and Paeoniae Radix, the diethylether extracts of these medical herbs were scanned spectroscopically and the following results were obtained. Little is distinguishable when the diethylether extract of medical herbs was scanned from 190 ㎚ of wave length to 900㎚. Filtration of the extracts through ordinary filter paper was also of no help. Treatment of the diethylether extracts with active carbon enabled the authors to distinguish the two extracts; in scanning for the above wave length, it was found that from the wave length of 375 ㎚ up to 900㎚ the extract of Panax ginseng absorbed the light by about five times more than that of Paeoniae Radix. At these wave lengths the treatment with active carbon enables the distinction of two herbs.