The Dahongshan iron-copper deposit is hosted in metavolcanic to metasedimentary rocks of the Paleoproterozoic Dahongshan Group. Up to now, the genesis and tectonic environment of these ore-bearing rocks have been still controversial, which seriously restricts the understanding of the metallogenic mechanism and process. In order to identify the original rock types and diagenetic tectonic environment of these host rocks, the authors systematically studied major, trace and rare earth element compositions of main ore-bearing metamorphic rock series, including the meta-sodic volcanic rocks, mica schists and marbles, as well as the gabbro-diabase rocks. According to the results obtained, the ore-bearing rocks are characterized by poor K, Ti and rich Na, the meta sodic volcanic rocks are relatively depleted in Ba, Sr and Ti, weakly depleted in Zr, Hf and Nb, and are enriched in Th, Nd, Sm and La; their total content of rare earth elements are generally low, with LREEs relative enrichment(LREE/HREE=1.84~9.43), significant Eu positive anomalies(δEu=0.91~3.59, mean=1.62), and no obvious Ce anomalies. These characteristics are similar to those of rocks from jet deposition or high temperature submarine volcanism in the modern mid-ocean ridge or intracontinental rift. According to the comprehensive study, the protolith of mica schist may have been a calcareous mudstone, while the protoliths of meta-sodic lavas and meta-sodic tuffs are volcanic rocks which erupted in the bathyal environment, with high Na content. Meta-sodic volcanic rocks and gabbro-diabase rocks show similar anorogenic features to the magmatic rocks in the same period of Kangdian area, indicating that they are all products of magmatic activities in the same continental rift environment which may represent the Columbia supercontinent cracking process on the western margin of Yangtze block. The continental breakup generated some channels for the migration of mantle-derived magma, and provided a good material basis for the formation of the iron copper polymetallic metallogenic belt in Kangdian area.