Even if temporal gravity variations mainly result from mass transfers within the geofluid envelops, they also result from mass redistributions in the solid Earth and thus those associated with large earthquakes. It has been shown that the gravity signature of large earthquakes can be detected in satellite gravity data such as the GRACE mission or future, more-accurate ones. The GRACE satellite mission has been measuring the Earth's time-varying gravity field since 2002. The analysis of GRACE data allowed detailed study of the co-seismic and post-seismic phases of the large earthquakes that struck the Sumatra area in December 2004 and March 2005 and revealed some previously undocumented post-seismic processes occurring in the mantle. Results of these investigations on these large events and on others show that satellite gravity data perfectly complement ground based geodetic data. In particular, they provide unique information for oceanic areas where little or no ground data are available. Satellite gravity data are also very well suited for studying silent earthquakes. Finally it appears that satellite gravity time series can be also used to investigate possible pre seismic effects, especially for monitoring of locked subduction zone where large events could occur. All these results confirm the significant potential of GRACE type temporal gravity field data for earthquake studies from space and for possible monitoring of locked asperities of subduction zones.