The earliest book on science of animal husbandry in China elaborating the way to tell good horses from the inferior ones is Xiang Ma Jing (Classics of Identifying the Thoroughbred). Xiang Ma Jing(相马经 xiàngmǎjīng) said to be the work of an unknown author in the State of Chu(楚国 Chǔguó) in the late Warring States Period(战国晚期 Zhànguó wǎnqī). The book was later lost. People of later generations could only read from ancient records about the book without knowing its specific contents. In 1973, archaeologists found in Mawangdui Han Tomb No.3(马王堆三号汉墓 mǎwángduī sānhào hànmù) in Changsha(长沙 Chángshā), Hunan(湖南 Húnán) a silk manuscript that was confirmed to be the long lost Xiang Ma Jing. The book contains three chapters in 77 lines, totaling up to over 5200 characters. The first chapter states how Bo Le(伯乐 Bó Lè) identifies a good horse; the second chapter tells how to tell a good horse from its eyes, that is to say, to conduct a comprehensive research on the size, fullness, luster, movement of horse eyes as well as the eyelashes and ocular muscles to judge the physical ability and running speed of a horse; finally, the last chapter serves as an interpretation to Chapter One.

There is no doubt that the earliest book on horse science in China - Xiang Ma Jing has exerted great influence on the research of the ancient Chinese graziery.