The contents of Zhang Zhongjing's works Treatise on Exogenous Febrile Disease,the Jade Case Classic of the Golden Cabinet,and Essentials from the Golden Cabinet(collectively known as the three classical medical books of Zhang Zhongjing),as well as Important Formulas Worth A Thousand Gold Pieces and Supplement to"Important Formulas Worth a Thousand Gold Pieces",which were cited in the Arcane Essentials from the Imperial Library(Wai Tai Mi Yao Fang)during comparative proofreading were analyzed.Wai Tai Mi Yao Fang is a book edited and public by the Bureau of Revising Medical Books in Northern Song Dynasty.The contents in the collation records for Wai Tai Mi Yao Fang were compared to the original text of the above five classical medical books proofread in Song Dynasty.The results showed that:(1)the ministers of Song Dynasty which were in charge of the proofreading mainly took the previously-proofread books as references,and widely referenced to the other editions of Wai Tai Mi Yao Fang,which reflected the proofreading principles of the Bureau of Revising Medical Books in Northern Song Dynasty,i.e.,collecting various editions widely and then identifying similarities and differences;(2)the analysis of the collation record in Zhongjing's Treatise on Exogenous Febrile Disease by using comparative proofreading method plus reasoning proofreading method showed that,the medical knowledge of the ministers of Song Dynasty had some limitations;(3)some of the medical terminology used by the ministers of Song Dynasty in their collation record influenced the naming convention of later generations of medical science,for example,making the Piyue Pills be the synonym of the Maziren Wan(Maren Wan).The results indicated that the complexity and uncertainty of the textual content of the popular edition of Wai Tai Mi Yao Fang should deserve the attention,and their influences on the development of later generations'scholarship need further in-depth study.