A detailed investigation on 3D spatial distribution rules of Banded Iron- bearing Formation(BIF) with methods of gravity- magnetic inversion and 3D modeling of iron mine is presented based on the former analysis in the Anshan- Benxi area． Three dimension spatial distribution types of BIF are concluded as hook- like，tabular- like and“W” - like． BIF was mainly developed in three types of space including (1) the syncline cores，(2) cover coverage area，and (3) the deeper buried area where the range of tectonic uplift is small． The influences of tectonism，magmatic intrusion and uplift- erosion on the spatial distribution shapes of BIF are clarified．