The type description noted the taxon's similarity to the Monogolian ankylosaurids Saichania chulsanensis and Tarchia gigantea, and suggested that these three taxa form a clade within the subfamily Ankylosaurinae.
Some authors have suggested that Tianzhenosaurus is actually a junior synonym of Saichania chulsanensis, but this matter remains unresolved, and Vickaryous et al. (2004) placed it within the Ankylosauridae, nested as the sister group to Pinacosaurus.