Abstract：According to the tectonic deformation features of a medium- and lower-grade metamorphic series in the Huzhong area, Da Hinggan Mountains, five tectonic slices are distinguished. They underwent two phases of tectonic deformation. In the early phase extension changed the basic structure of the original strata. In the late phase, in the contractional regime strong thrusting-compression resulted in displacement and overlapping of tectonic slices and thus made the strata wide non-Smith. According to the deformation features of different rock associations, eight tectonostratigraphic types are recognized. On that basis, combined with the characteristics of rock associations, the authors establish the tectonostratigraphic units-the Jixianggou formation-complex and Dawangzi formation-complex. The two formation-complexes are called the Wolegen Group-complex.