Abstract: With the magnetic measurements as main method and the density as auxiliary one，the paper studies the relationship between susceptibility and density of iron-copper ore in the Moon Mountain iron copper deposit in Chile，it is considered that the rock and ore in the area can be divided into four categories:magnetite(hematite) type，copper-bearing magnetite type，hematite (specularite) type and breccia type; the magnetic susceptibility of the ore show a positive correlation with its density and TFe content in the area.The higher TFe content is，the greater magnetic susceptibility and density will; The lower TFe content is，the lower magnetic susceptibility and density will be.In the later prospecting work in the Moon Mountain mining area，the abnormal zone with high density and high magnetic susceptibility of magnetite (hematite) and copper-bearing magnetite，and the abnormal zone with high density and low magnetic susceptibility of hematite and specularite are delineated to position the prospecting target area，which is an excellent prospecting method.

Key words: Magnetic susceptibility, Density, Total iron content, Iron-copper ore area, Moon mountain, Chile