Xu Zhongyuan is known through the book San Yi Bi Tan (Random Notes on Three Kinds of Wonders). Beyond this, public information is limited: his birth and death years, native place, and life story are all unknown. Judging from the surviving work, he was an author of notebooks and miscellaneous records. San Yi Bi Tan, classified under culture, deals largely with strange tales and miscellaneous matters, written in the manner of traditional notebook sketches that combine accounts of the supernatural with anecdotes and historical gossip. Such works usually consist of short entries linked together, drawing on a wide range of material in plain language. They reflect the author's interest in marvels and oddities and preserve fragments of contemporary customs and hearsay, offering some reference value for understanding the character of traditional notebook writing. Because records are scarce, knowledge of the man and his book still depends mainly on San Yi Bi Tan itself.
