The Gongchangling iron deposit is representative of the Anshan-type sedimentary-metamorphic iron deposits. The analyzed and contrasted the major elements, trace elements, rare earth elements of chlorite schist, garnet-chlorite schist and chlorite-garnet, and iron contents of chlorite, garnet and biotite. The results indicate that the Al-bearing argillaceous and silty material of Fe-bearing rocks, which occurred during deposition intermittent periods, played an important role in introducing silicon from magnetite quartzite to form garnet, chlorite and biotite.