Geosynchronous Synthetic Aperture Radar (GEO SAR) has the advantages of short revisit period and wide coverage,and has great potential in disaster prevention and mitigation.In this paper,a distributed GEO SAR system containing both close and sparse formation is proposed.On the basis of monostatic GEO SAR,multiple phase centers are formed by adding companion satellites only receiving signals,which has the advantages of rich tasks and low cost.However,different tasks require different spatial baselines for formation.Aiming at the configuration of close formation,this paper proposes a method of correcting the relative motion equation based on coordinate rotation,through which the analytical expression of spatial baseline under the influence of earth rotation can be obtained;furthermore,a method of linear time-varying baseline design based on semi-major axis correction is proposed,which can be applied to SAR tomography.For sparse formation,the minimum Position Dilution of Precision criterion under the measurable constraints of global scene is proposed,which can realize the design of sparse formation with the best combination of line of sight (LOS) thus can achieve the best three-dimensional (3D) deformation retrieval performance.Finally,the system performances of the designed distributed GEO SAR formation are simulated and analyzed,including the diurnal variation of baseline,the resolution in altitude direction and the 3D deformation retrieval accuracy in typical observation areas.