Rouputuan, also known as Huiquanbao and Juehouchan, and translated as The Carnal Prayer Mat or The Before Midnight Scholar, is a 17th-century Chinese erotic novel published under a pseudonym but usually attributed to Li Yu.

The novel had a controversial status in Chinese literature, and has long been banned and censored; recent scholarship treats the work as an allegory which uses its unabashed pornographic nature to attack Confucian puritanism.

"Unrealised One" or "Unfinished One"), visits a Buddhist temple, where he meets a monk, who notes that he exhibits wisdom but also lust.

"Monk with a Cloth Sack") once urged him to give up on his philandering ways and follow the path of Buddhism, while his father-in-law, the Taoist Tiefei (鐵扉道人), also attempted to persuade him to be more decent, but Weiyangsheng ignored both of them.

Later, he realises that he has committed grave sins and decides to show penitence by becoming a monk and studying under Budai Heshang.

However, the first chapter seems to express the view that "sex is healthy, not devitalising, as in the traditional Chinese assertion, so long as it is 'taken' as if it were a drug, and not 'consumed' as if it were an ordinary food".

They further point out that in modern times Lu Xun suggested that the novel had a spirit and style akin to Li's, but he did not elaborate.

The Changs acknowledge Patrick Hanan's conclusion that "so distinctive is his brand of fiction that although the novel has never actually been proved to be by Li Yu, one has only to read it alongside his stories to feel the truth of the attribution."

[6] Robert E. Hegel wrote that The Carnal Prayer Mat was intended to satirise the imperial examination system and parody the patterns in caizi jiaren novels.