Xu xuanguailu 續玄怪錄 "Continued tales of mysteries and monsters" is a collection of stories compiled during the Tang period 唐 (618-907) by Li Fuyan 李復言 (fl. 800). Of his life, not much is known. He seems to have lived during the Dahe 大和 (827-835) and Kaicheng 開成 (836-840) reign-periods and hailed from Longxi 隴西 (modern Lintao 臨洮, Gansu). Around 830, he travelled to the region of modern Sichuan, where he met the scholar Shen Tianxiang 沈田相 and decided to write a kind of supplement to Niu Sengru's 牛僧孺 (780-848) Xuangailu 玄怪錄. Some scholars assume that Li Fuyan was identical to Li Liang 李諒 (775-833), who was military commissioner (jiedushi 節度使) of Lingnan 嶺南 and was befriended to Bai Juyi 白居易 (772-846) and Yuan Zhen 元稹 (779-831). Yet, this identity of the author is unlikely because of many discrepancies between Li Liang's poetry collection Hang Yue ji he shi ji 杭越寄和詩集 and the Xu xuanguailu.
The Xu xuanguailu includes many famous stories, like the elegantly written tale Xin Gongping shang xian 辛公平上仙, the transformation of a man into a fish in Xue Wei 薛偉, the metamorphosis of a man into a tiger in Zhang Feng 張逢, the story of the marriage of Wei Gu 韋固 in Dinghundian 定婚店, or General Li Jing's 李靖 (571-649) acting as the God of Rain.
The imperial bibliography in the official dynastic history Xintangshu 新唐書 lists the Xu xuanguailu with a length of 5 juan (or ten semi-fascicles). The book catalogue Junzhai duzhu zhi 郡齋讀書志 says that it was divided into two chapters, namely Xianshu 仙術 "The skill of immortality", and Ganying 感應 "Retribution in a later life".
The received version has a length of 4 juan and includes 23 stories. This version is a later compilation and not identical to the original. This is evident in quotations in the encyclopaedia Taiping guangji 太平廣記 that are not included in the modern edition. The Xu xuanguailu was often printed together with the Xuanguailu, so that it is frequently not clear whether a story was included in the former or the latter.
The Xu xuanguailu is included in the series Shuofu 說郛, Wuchao xiaoshuo 五朝小說, Tangren shuohui 唐人說薈, Tang-Song congshu 唐代叢書, Longwei mishu 龍威秘書, Xu guyi congshu 續古逸叢書, Sibu congkan xubian 四部叢刊續編, Linlang mishi congshu 琳瑯秘室叢書 and Sui'an congshu 隨庵叢書. A modern version was published by the Zhonghua Shuju Press 中華書局 in 1982.