Abstract: High precision magnetic study shows that distinct rules exist in the magnetic features of northern Chifeng area, Inner Mongolia. Based on a series of conventional data processing and wavelet transformation, anomalous field is separated, it is suggested that there are different origins of volcanic and intrusive rocks of different phases, which displays different magnetic feature. Through further comparison with gravity data, the properties of igneous rocks are identified, furthermore, spatial distribution and properties of the rocks are deduced. In the western part, it′s mainly composed of shallow surface igneous rock and deep intrusive rock, while in the middle-east part, it′s dominated by intrusive rock of both shallow and deep origin.