Lóng Rénfū 龍仁夫 (1255–1335), zì Guānfù 觀復, hào Línzhōu 麟洲, was a late-Sòng / Yuán Yìjīng scholar from Jí’ān 吉安 (Jiāngxī 江西); the Sìkù notice gives him as a man of Lúlíng 廬陵, while the Jí’ān fǔ zhì 吉安府志 specifies the more precise locality of Yǒngxīn 永新. He held the Yuán-period office of educational intendant for Confucian learning in Húguǎng 湖廣 (Húguǎng rúxué tíjǔ 湖廣儒學提舉). The Yuán shǐ 元史 records that “what Rénfū wrote on the Zhōuyì in many places brought out what earlier Confucians had not brought out,” a judgment endorsed by the Sìkù editors.
His chief surviving work is the Zhōuyì jízhuàn 周易集傳 (KR1a0082), originally in eighteen juàn but transmitted incomplete in eight juàn through the Sìkù quánshū; the upper and lower scriptural sections together with the Tuàn 彖 and Xiàng 象 commentaries are essentially complete in the surviving recension. The work was completed in zhìzhì xīnyǒu 至治辛酉 (1321). Lóng’s method, as the Sìkù notice frames it, takes the Chéng–Zhū tradition as its base but goes beyond mere paraphrase, deriving meaning directly from the symbols of the hexagrams and their lines. His reading of the Záguà 雜卦 as a divinatory text — supported by Chūnqiū zuǒzhuàn 春秋左傳 citations of single-character hexagram judgments (e.g. zhūn 屯 = firm, bǐ 比 = enter, kūn 坤 = peaceful, zhèn 震 = killing) — is singled out as an original contribution.