Abstract: While using the Beijing GNSS station network to monitor earthquake activity, some necessary processing must be carried out such as more accurate solution, corrections to the replacement of equipment, ultra poor and relocation, and elimination of the Ecomponent trends applying empirical algorithm. The E component of the 16 available stations showed a lower triangular w ave abnormality before the 2011 Tohoku Mw9.0 earthquake, a step change during the earthquake and a Q-shaped recovery after the earthquake. The whole steps constitute a complete seismic process that rarely seen in the past in the GNSS observations. It provided a perfect example for further study. Especially the step changes during the earthquake moves to the east rapidly, which will not be influenced by man- made normal values and may play a significant role in the earthquake forecasting and early warning.

Key words: Coulomb failure stress changes, Interactions between faults, The 2008 Wen-chuan 8.0 earthquake, The 2013 Lushan 7.0 eart hquake, The Longmenshan fault zone