The Mang is an isolated population living at the border of Vietnam and China characterized by small stature and a primordial lifestyle. However, the origin of this population remains unclear. To clarify the origin of the Mang and its genetic relationship with other populations, 20 Y-chromosome markers were analyzed, including 12 biallelic markers and eight short tandem repeats (STR) in this population, and the data compared with published data from other populations in eastern Asia. Only three Y-chromosome haplogroups, O2a*-M95, O3d-M7 and O3e-M134, were identified in Mang. Among them, the southern haplogroups O2a*-M95 were most prevalent, with a frequency of 97%. Principal component analysis (PCA) plots showed that Mang clustered with southern populations but not with northern populations. In conclusion, the present study provided evidence for the first time that the Mang population is of southern origin.