Residual magnetic anomly in southern part of Heishilazi iron deposit is a subject to which much attention has paid.The paper analyzes metallogenic setting,ore-control factors and characteristics of the iron deposit and calculates quantitatively the magnetic anomly.Geological-geophysical inference is made on the deposit and it is inferred that dip of iron ore body to depth is overturned.The inference could explain effectively the residual magnetic anomly in the mining district and make clear of location of deep ore bodies for further exploration and predict much more mineral resource to depth of the mining district.Lage volume of iron resource.