Euroasian wild boar (Sus scrofa) is widely distributed throughout Southern Europe, Asia, and North Africa in Scrub, forest, and arid environments. Even though wild boars are biologically and genetically well-studied worldwide, so far no genetic studies have been conducted in Mongolia. Two subspecies of wild boars including Sus scrofa nigripis and Sus scrofa raddeanus are known in Mongolia based on their morphological differences. Then we needed to test genetic differentiation between those subspecies and compare geographically close populations in Mongolia using mitochondrial DNA complete cytochrome b gene. We also retrieved sequences of wild boars in the neighboring countries from Genbank to do phylogenetic relationships. Wild boars’ tissue samples were collected from ten provinces throughout the distribution regions of wild boars in Mongolia. In result of the research, Sus scrofa nigripis showed a significant genetic difference as a subspecies. In conclusion, this research proven that there are two subspecies of wild boars in Mongolia according to the mtDNA data. Although our data can be enough to provide that Sus scrofa nigripis fits with the criteria of Evolutionary Significant Unit (ESU), in future big sample size based on non-invasive sampling method from those populations will be useful to identify the further questions.