Wú Zhèngzǐ 吳正子, hào Xīquán 西泉, was a Southern Sòng (Xiàozōng-period, 1163–1189) literary scholar of unrecorded biographical details. The principal evidence for his period is his own wàijí opening note in the commentary on Lǐ Hè (KR4c0062) reporting “I once heard Xuē Chángzhōu (Xuē Jìxuān 薛季宣, zì Chángzhōu, 1134–1173) say…” — situating Wú as a Qiándào / Chúnxī contemporary of Xuē. Wáng Qí’s authoritative Qīng Lǐ Chángjí gēshī huìjiě explicitly identifies Wú’s annotations as the oldest surviving stratum of Lǐ Hè exegesis.
Wú’s Jiānzhù Lǐ Chángjí gēshī — preserved in the WYG copy (KR4c0062) layered with Liú Chénwēng’s 劉辰翁 later píngdiǎn (critical marks, added late 13th century) — is the foundational document of the Lǐ Hè commentary tradition. His commentary method is restrained and sober: gloss the allusions where they originate, do not force semantic interpretation onto Lǐ’s deliberately oblique imagery. The Sìkù tíyào prefers Wú’s restraint over the more aggressive MíngQīng commentary tradition.
No other works are recorded under his name. CBDB has no matching entry.