Abstract: A new national record of Corydalis vaginans Royle was documented during the taxonomic identification of specimens collected from Pulan County, Xizang Autonomous Region, China. Based on these specimens, detailed Chinese morphological description and photographic documentation of the species are presented for the first time. Corydalis vaginans belongs to Sect. Ramoso-sibiricae s.s. and bears close morphological affinity to C. cornuta Royle. Distinguishing characteristics of C. vaginans include leaf blades typically triangular in outline, papillae along abaxial veins, ultimate lobes usually lanceolate (vs. leaf blades usually triangular-oblong in outline, abaxially glabrous, ultimate lobes usually broadly obovate in C. cornuta); crests of outer petals dentate, narrow to broad, inner petals tipped concolorous (vs. narrow crests of outer petals entire, inner petals usually tipped with blackish purple in C. cornuta); capsule broadly obovate, pedicels 4–10 mm, seeds shiny, smooth (vs. capsule oblanceolate to broadly obovate, pedicels 2–5 mm, seeds dull, punctulate in C. cornuta). This record expands the known geographic distribution of C. vaginans and contributes valuable data for ongoing taxonomy and resource utilization of the genus Corydalis.