The different altitudes upward continuation of the recently surveyed aeromagnetic anomalies in central and western Qinghai Tibet plateau revealed an extremely distinct NNEtrending negative magnetic anomaly zone in the eastern part of the surveyed area, i.e., in the vast area extending from Qaidam southwestward within central Qinghai Tibet plateau. According to an analysis of the aeromagnetic regional field in combination with man made earthquake, Moho depth calculated by gravity, hydrothermal activity, recent volcanic activity, morphologic characteristics and natural seismic activity, it is held that the upward migration of deep heat flow in NNEdirection caused local melting of magma and hence the rising of geotemperature in the lower part of the upper crust, which led to the demagnetization at the bottom of the magnetic bed, the appearance of negative magnetic anomalies, and the acceleration of the uplifting of Qinghai Tibet plateau. All this has provided new evidence for the study of the formation and evolution of the plateau.