Abstract: There are a variety of genetic types of tagilovite in the furnace smelting slag of vanadium titanium magnetite. through the mineral optical properties, X-ray diffraction analysis, microanalysis, it was found that the different genetic types of tagilovite belongs to artificial solid solution minerals of ilmenite-hematite. Furthermore, through the calculation of chemical formula, it was proved that the tagilovite was the product of the reducing atmosphere weakened.