It is generally believed that Ziyi Bencao is a book of the pre-Qin period. By studies on several aspects, including ancient bibliographical records, relics unearthed in Mawangdui Han tombs, nomenclature of ancient book titles, the date of appearance of ancient classics, contradictions between the time of activities of Bian Que and Ziyi, it is concluded that, in the pre-Qin period, there were no classic of herbology of any kind, even less Ziyi Bencao. The books entitled Ziyi Bencao recorded in bibliographies after Han Dynasty are all apocryphas made by Han authors.