Abstract: This paper summarizes some of the main research progresses on earthquake electromagnetic precursors based on ground and space observations, and reviews the research findings on ground based earthquake electromagnetic precursors in several aspects such as resistivity, geo-electric field, geomagnetic field and electromagnetic disturbance. Taking the DEMETER satellite as a research object, the paper introduces the research progress on space-based electromagnetic precursors in aspects of electric field, magnetic field and other physical parameters, and it also summarizes the research outcomes in joint processing of space-based and ground-based electromagnetic data, points out that the electromagnetic anomalies of ground-based and space-based earthquake electromagnetic precursors have good consistencies in both time and tendency. The joint-analysis of ground and space based earthquake electromagnetic precursor information possesses significant theoretical guidance for future earthquake monitoring and forecasting.