Ancient DNA was extracted from 13 skeletal remains from the burial groups of Khitan nobles, which were excavated in northeast China. The hypervariable segment Ⅰ sequences(HVSⅠ) of the mitochondrial DNA control region, in the 13 individuals, were used as genetic markers to determine the genetic relationships between the individuals and the genetic affinity to other interrelated populations by using the known database of mtDNA. Based on the phylogenetic analysis of these ancient DNA sequences, the genetic structures of two Khitan noble kindreds were obtained, including the Yel Yuzhi′s kindred and the Xiao He′s kindred. Furthermore, the relationships between the Khitan nobles and some modern interrelated populations were analyzed. On the basis of the result of the analysis, the gene flows of the ancient Khitans and their demographic expansion in history was deduced. Ancient DNA was extracted from 13 skeletal remains from the burial groups of Khitan nobles, which were excavated in northeast China. The hypervariable segment I sequences (HVS I) of the mitochondrial DNA control region, in the 13 individuals, were used as genetic markers to determine the genetic relationships between the individuals and the genetic affinity to other inter- linked populations by using the known database of mtDNA. Based on the phylogenetic analysis of these ancient DNA sequences, the genetic structures of two Khitan noble species were obtained, including the Yel Yuzhi’s kind of and the Xiao He’s kindred. Moreover, the relationships between the Khitan nobles and some modern interrelated populations were analyzed. On the basis of the result of the analysis, the gene flows of the ancient Khitans and their demographic expansion in history was deduced .