In this paper a review is given of paleomagnetism, and its significance to geological and tectonio problems. The field of Paleomagnetism is outlined: both the earth magnetic field, the natural remanent magnatizations of rocks, and the geological applioations are discussed. The research on the magnetic anomalies in the oceans is presented with the oonsequent theories on spreading of the ocean floor, Finally, the concept of the new global tectonics gives a picture of the structural evolution of the earth, based on geological and geophysical data.