At the beginning of 2009, Peking University received more than 3,300 pieces of Western Han Bamboo Slips, which were named "Western Han Bamboo Slips Collected in Peking University". "Bamboo Books of Western Han Dynasty Collected in Peking University" was copied in the middle of Western Han Dynasty. The contents of bamboo slips are all recorded in ancient books, including nearly 20 kinds of documents, which basically cover the six categories of "Six Arts", "Zhuzi", "Poetry", "Military Calligraphy", "Numerology" and "Ji Fang" classified in Hanshu. The year number after Emperor Wu of the Han Dynasty was not found in the bamboo slips of the Western Han Dynasty, but only the year of "the first year of filial piety" was found on a bamboo slip of numerology. According to the characteristics of calligraphy style and the analysis of all bamboo books, scholars speculate that the copying age of these bamboo books should be mainly in the late Han Dynasty, and the lower limit should be no later than Xuandi. This batch of bamboo books in the Western Han Dynasty is another treasure house of ancient books in the Han Dynasty after Mawangdui silk books and Zhushan bamboo slips in the 1970s, which is of great academic value to the study of ancient Chinese history, ideology, culture, science and technology, calligraphy art and other fields. According to the plan, the Bamboo Slips of the Western Han Dynasty collected by Peking University will be published in seven volumes after finishing, and the Bamboo Slips of the Western Han Dynasty collected by Peking University (Lao Zi), which went online yesterday, is the second and first volume in the publishing plan. The third volume includes Zhou Xun, and Zhou Xun's discovery will "restore the true colors of Taoism in the pre-Qin period"