Abstract: The Cornu Antelopis as stated in Zhong Yao Zhi is the horn of Saiga tatarica L., family Bovidae. Most of these horns consumed in China as medicine are imported. It has been found that certain horns with similar appearance were used as adulterants or substitutes. In recent years, most of these horns have been found to possess similar pharmacological activities. It is very probable that many of these horns may come into commerce in the near future. Therefore, it is necessary to study their macro-and microscopical characters in order to distinguish them especially in sliced or powdered form. The horns mentioned above include those derived from Procapra gutturosa Pallas, Gazella subgutturosa Guldenstaedt and Pantholops hodgsoni Abel, all belong to the family Bovidae.These horns differ from the Rhinoceros horns mainly in the following respects:(a) The horn consists of a bony core and horny sheath, only the latter is used medicinally; (b) the horny sheath chiefly composed of a fundamental horny tissue which is a strongly developed horny layer of the frontal skin of the animal's head; (c) the fundamental horny tissue composed of many layers of flattened, scale like cells, is a more or less wavy structure; a bundle derived from hair-shaft is embeded in each peak of this wavy structure; (d) the bundles widely spaced in the fundamental tissue are lenticelar, triangular or roundish shaped in transverse section with only a few layers of flattened, scale-like cortical cells surrounding the medulla.However, the four horns may be distinguished from each other by the relative abundance and colour of the pigment granules present in the cells. The following key is suggested.1. Tissue colourless and transparent………………Cornu Saigae tataricae1′. Tissue coloured and untransparent2. Fundamental horny tissue cells containing many pigment granules black or dark brown in colour; cortical cells colourless…………Cornu Gazellae subgutturosae2′. Fundamental horny tissue cells containing more or less pigment granules brown or dark brown in colour3. Tissue dark brown in colour; cells containing many brown pigment granules densely distributed…………………………Cornu Pantholopis hodgsoni3′. Tissue pale brown in colour; cells containing a few brown pigment granules……………………………Cornu Procaprae gutturosae.