The deer resources in China are abundant, with seven species in the sub-family Cervinae distributing in various areas. The intraspecific phylogeny of Cervinae has been widely explored, while the evolutionary relationship among different species requires further efforts, in which only few molecular studies on ancient materials have been performed. In this study, we carried out ancient DNA research on two Cervinae subfossils from northeastern China, dating of 3800 and 5100 aBP. Through ancient DNA extraction, double-stranded sequencing libraries construction, next-generation sequencing and bioinformatics data analysis, we reconstructed two mitochondria sequences with lengths of 16475 bp (GenBank accession number: MT784751, sequence integrity: 99.83%) and 16167 bp (GenBank accession numberh: MT784752, sequence integrity: 97.96%), respectively. Based on the mitochondrial homologous sequences of the extant Cervinae species in GenBank, we constructed a phylogenetic tree. The results show that: 1) both the average length and the C-to-T substitution frequencies at 5’- end of the NGS short reads indicate the data are from ancient specimens; 2) the two ancient individuals clustered with Cervus elaphus in the phylogenetic tree, and were molecularly identified as C. elaphus; 3) the two ancient samples from Heilongjiang are phylogenetically close to the extant C. elaphus alxaicus, but far from the extant C. elaphus xanthopygus. Combining the dates of the samples, we suggest that these two samples represent a population of ancient C. elaphus in Heilongjiang, which was not the direct maternal ancestor of the extant C. elaphus xanthopygus.