[Objectives] Wolf Snakes of the genus Lycodon represent a major snake radiation in Asia. While recent studies have made major progress on the taxonomy of the genus, distributions of recognized congeners warrant further revisions. The main objective of the current paper is to assess the taxonomic status of the Lycodon populations in western and southern Yunnan Province of China. [Methods] During the fieldwork between June and July in 2022, three specimens of snakes were collected from Yunnan, two of which are from Yingjiang County, and a single specimen is from Mengla County. Mitochondrial DNA fragment (Cyt b) was targeted and amplified using published primers, and the new results were combined with GenBank data to build the phylogeny of the genus and calculate genetic distances. Additionally, morphological data were collected from newly collected specimens and compared with literature. [Results] The two specimens from Yingjiang County were identified as Lycodon septentrionalis (Table 1, Fig. 1), which resurrect the removed record of the species from Yunnan. The single specimen from Mengla County was conspecific with the previously identified as “L. subcinctus” Boie, 1827 from China, but it showed considerable genetic distances from topotipic L. subcinctus from southeast Asia (Table 2), and the phylogenetic relationship with respect to true L. subcinctus remains unresolved. Due to the lack of morphological diagnosis, the Mengla specimen was tentatively assigned as L. cf. subcinctus, which supported the neglected, questionable record of the species in Yunnan. [Conclusion] Based on our discovery, we discuss the distributional history of L. septentrionalis in Yunnan, indicating that both L. chapaensis and L. septentrionalis are found in Yunnan, with the latter species only found in the very southwestern corner of the province. Moreover, we show that the Chinese population of the previously identified “L. subcinctus” represents a cryptic species that warrant further integrative studies. Lastly, based on the results, we support the previous biogeographic hypothesis that Southwestern Yunnan is similar to southeastern Tibet zoogeographically, and we suggest that future research direction for herpetological surveys in Yunnan should focus more along the border regions in the south.