Qīngsù 清素 was a Tang-period Cí’ēn / Fǎxiàng commentator known almost exclusively for his joint authorship (with 澄淨 Chéngjìng) of the 32-fascicle Yúqié shī dì lùn yìyǎn 瑜伽師地論義演 (KR6n0015) — a major lemma-by-lemma commentary on the first 32 juǎn of KR6n0001 Yogācārabhūmi. Preserved through the Jin-dynasty (金) Edition of the Canon (the Guǎngshèngsì 廣勝寺 deposit at Zhàochéng 趙城, Shānxī) and recovered in the twentieth century, the work transmits a stream of late-Tang Cí’ēn exegesis otherwise largely lost. No biographical information about Qīngsù survives independently; his dating is inferred from internal references to 窺基’s and Huìzhāo’s commentaries (which pre-date his work) and the Jin-dynasty manuscript tradition (which post-dates it). He was probably active in the second half of the eighth or early ninth century.