Three specimens of the genus Plestiodon were collected during herpetological surveys of Fuzhou City in Fujian and Wenshan Zhuang and Miao Autonomous Prefecture in Yunnan, China. These specimens were identified as P. tamdaoensis based on both morphological diagnosis and phylogenetic monophyly of concatenated mitochondrial COI and ND1 gene fragments, and they represented new distribution records of P. tamdaoensis in Fujian and Yunnan provinces. The newly discovered individuals showed minimal uncorrected genetic distances (p-distance ≤ 0.6%) and minor morphological variation in pholidosis characters compared with topotypic and taxonomically confirmed individuals of P. tamdaoensis. Furthermore, our phylogenetic analyses showed that the previously identified P. cf. elegans from Ninh Binh Province, northern Vietnam was nested within the clade of P. tamdaoensis, suggesting a conspecific relationship (Fig. 1). This also constitutes a new provincial record of T. tamdaoensis from Ninh Binh Province in Vietnam. Our findings greatly expand the known distribution range of P. tamdaoensis. In addition, we discussed the potential impacts of our findings on the Red List Conservation Assessments of P. tamdaoensis in China and the potential ranges of species with similar distribution patterns in China, providing guidelines for future focal herpetological surveys.