It is considered to be part of the group of "giant deer" (often referred to collectively as members of the tribe Megacerini), with a close relationship to Megaloceros.

[11] Sinomegaceros has often been considered closely related to other genera "giant deer", like Praemegaceros and Megaloceros, as part of the tribe Megacerini.

[12] Mitochondrial genomes from Late Pleistocene Chinese and Siberian Sinomegaceros (including S. ordosianus and S. pachyosteus) indicate that the mitochondrial diversity of the Irish elk (Megaloceros giganteus, also known as the giant deer) is nested within the diversity of Sinomegaceros, suggesting that the two lineages interbred after their initial split.

[17] Radiocarbon dates for S. ordosianus in Northeastern China extend as recently as the Last Glacial Maximum, around 22,000 years ago.

[13] Remains of S. yabei at Lake Nojiri in Nagano Prefecture of Honshu, Japan, dating to approximately 37,900 to 42,600 years Before Present have been found associated with spear-shaped wood pieces and large pebbles, with the long bones fractured, with their fragments bearing percussive marks, suggesting that these deer (alongside elephants belonging to the species Palaeoloxodon naumanni) were butchered by humans at the site, with the long bones likely cracked to extract bone marrow.

[18] S. ordosianus is suggested to have likely been hunted by archaic humans, based on the finds of its remains in Chinese Paleolithic archaeological sites.