Xixi congyu 西溪叢語 (also written 西溪藂語) "Dense talks of West Creek" is a "brush-notes"-style book (biji 筆記) written during the early Southern Song period 南宋 (1127-1279) by Yao Kuan 姚寬 (1105-1162), courtesy name Lingwei 令威, style Xixi 西溪, from Shengxian 嵊縣 in the prefecture of Yuezhou 越州 in today's Zhejiang province. He inherited (yinbu 蔭補) the office of his father Yao Shunming 姚舜明 as Vice Minister of Revenue (hubu shilang 戶部侍郎), edict attendant of the Hall of Exemplary Strategies (Huiyouge daizhi 徽猷閣待制), Vice Director of the Revenue Bureau of the Imperial Secretariat (shangshu hubu yuanwailang 尚書戶部員外郎) and finally a junior compiler in the Bureau of Military Affairs (shumiyuan bianxiuguan 樞密院編修官). Yao Kuan was known as a well-educated person and was a fine poet and calligrapher. He once wrote a book on crossbows, Nushoushu 弩守書 and commentaries on the history books Shiji 史記 and Zhanguoce 戰國策 (all lost). His collected writings are called Xixi ji 西溪集.
The Xixi congyu with a length of 3 juan is mainly a critique and collation of statements in older writings, or transmitted versions of them. The circulating version of the anthology Wenxuan 文選, for instance, in the rhapsody Shennü fu 神女賦, used the character 王 instead of the word 玉. Lu Ban's 劉攽 (1022-1088) opinion that Xiao He 蕭何 (d. 193 BCE) had not worked in the local labour section (gongcao 功曹) is pointed out as wrong. With the argument of rhyme laws, Yao doubts Cao Tingjian's 曹庭堅 argument that the word gui 瓌 in a poem of Xu Hao 徐浩 (703-782) should be replaced by the word nu 奴. And he demonstrated that Wang Anshi 王安石 (1021-1086) wrongly interpreted the words tongguan 彤管 "red pipe" as xiaosheng 簫笙 "flutes and mouth organs" in his commentary Shijing xinyi 詩經新義. Yao did, however, also make mistakes. The contemporary scholar Ye Shi 葉適 (1150-1223) highly regarded Yao Kuan's studies.
The books is found in the series Baihai 稗海, Siku quanshu 四庫全書, Jindai mishu 津逮秘書, Xuejin taoyuan 學津討原, Xiaoyuan congshu 嘯園叢書, Hanfenlou miji 涵芬樓秘籍, Biji xiaoshuo daguan 筆記小說大觀, Congshu jicheng chubian 叢書集成初編, Shuofu 說郛, Wuchao xiaoshuo 五朝小說 and Wuchao xiaoshuo daguan 五朝小說大觀.
Lu Xinyuan 陸心源 (1838-1894) wrote a critical commentary, Xixi congyu jiao 西溪叢語校, which is included in the collection Qianyuan zongji 潛園總集.