[Objectives] Yanbian Keelback SnakeHebius yanbianensis was described based on one specimen, after then, three specimens from Yanbian County in Sichuan Province and three from Yongren County in Yunnan Province were reported. Owing to the limited information of this species, its genetic differentiation, morphological characters, and distribution require to be further studied. [Methods] Based on 20 specimens newly identified from Sichuan and one newly collected from Yunnan, together with seven specimens mentioned above (Table 1 and Fig. 1), we constructed Maximum Likelihood (ML) and Bayesian Inference (BI) phylogenetic trees inferred from Cyt b gene sequence by IQ-TREE 1.6.12 and MrBayes 3.2.1 respectively, calculated genetic distance by uncorrected p-distance in MEGA 11, and conducted morphological measurements and scales counts.[Results] The result of molecular phylogenetic analysis inferred from Cyt b gene sequence (Table 2) showed that H. yanbianensis from Binchuan in Yunnan and Yanbian in Sichuan clustered into one lineage (SHR 99 / UFB 100 / BI 100) (Fig. 2), but the uncorrected p-distance of 1.4% was recognized between them, which is much lower than the interspecific p-distance between 4.5%﹣14.2% of Hebius (Table 3), indicating intraspecific genetic differentiation. The morphological characters of specimens from different locations are generally similar, but there are some variations:(1) total length (TaL) 48.2﹣83.6 (+) cm, tail length (TL) 12.3﹣21.4 (+) cm, tail length/total length (TL/TaL) 25.5%﹣36.2%; (2) supralabials (SL) usually 8 (7 or 8), infralabials (IL) usually 10 (8﹣11), preoculars (PreO) usually 2 (1﹣3),postoculars (PostO) 3, anterior temporals (aTem) usually 2 (1 or 2); (3) dorsal scales (DSR) 19-19-17, ventral scales (VEN) 159﹣175, subcaudal pairs (SC) 67﹣90; (4) anal 1, divided; (5) maxillary teeth (MT) 23﹣25, the last two distinctly enlarging, without diastema; (6) dark brown or tan on the back, dorsal scales inlaid with bright yellow or red-orange spots or patterns, occasionally individual’s coloration composed discontinuity dorsal stripes or faded; (7) milky white or yellow on the venter, occasionally individuals scattering stain spots, on the outer side of the ventral scale each having large black triangle spots composing strong ventrolateral series (Table 4 and Fig. 3 & 4). It can be distinguished from the other 23 Hebius species distributed in China by tail length/total length, dorsal scale rows, ventral scales, subcaudals, dorsal patterns, and ventrolateral stripe (Table 5). The geographical distribution of H. yanbianensis was found not only at Yanbian and Yongren, but also at Miyi, Huili, and Jiulong in Sichuan and Binchuan in Yunnan (Fig. 1). [Conclusion] This study provides external morphological description and conducts molecular systematics of H. yanbianensis from different populations, revealing that the morphological characters of H. yanbianensis are generally stable, and a certain genetic differentiation exists in different geographic populations.