Abstract: We outlined the method to evaluate seismic hazards of active faults according to the coulomb failure criteria using the GNSS, InSAR, gravity, leveling and other kinds of geodetic observations. The design for the corresponding evaluating system was presented. The system use these geodetic data to determine the crustal deformation near active faults and implement the inversion for the strain, stress and motion parameters of active faults. Then fix the threshold values of stress of active faults from geological and seismic data and analyze the sites, maximum magnitudes, recurrence time and probability of potential earthquakes using the evaluating models. The system exhibits, interprets, and manages the evaluating results using GIS. As a demonstration, we discussed the coseismic coulomb stress triggered by 2008 Wenchuan earthquake, the lasting time of stress disturbing and the earthquake rate of Longmenshan area after shock.