Abstract: Beiguo Ji is a collection of poems by Xu Ben, a poet in the late Yuan to early Ming Dynasties.
Beiguo Ji, a block-printed edition of the Ming Dynasty, Wanli Period, collected in Zhejiang University Library,
is the master copy of the Si Ku Quan Shu. Many proofreading notes inscribed by the editor and the proofreader
of the Si Ku Quan Shu are kept in the book. Its contents can be divided into three categories: marking
format, collating text and correcting nonstandard words. The inscriptions were written by editor Min Sicheng,
proofreader Lu Sui, the transcriber in charge of the three royal libraries in the south of China and so on. There
are many problems in Beiguo Ji of Si Ku, related to the selection of the master copy, the undutiful editor, the
personality of the proofreader, the excessive workload of the proofreader, the substitute scribe and so on. By
studying the master copy, we can observe the details in the process of Si Ku Quan Shu and have a glimpse of
the common limitations to reveal the important value of the master copy for the research of Si Ku Quan Shu.

Key words: Beiguo Ji, Si Ku Quan Shu, Master Copies of Si Ku Quan Shu, Zhejiang University Library