The Synthetic Aperture Radar (SAR) technology and its application have developed rapidly since the birth of the first SAR in April of 1960.The deepening and comprehensive technological utilization of different electromagnetic wavebands,polarization,amplitude and phase information,is characterized by the bi-static/multi-static or constellation observation,polarimetric SAR interferometric measurement,high revisit and wide swath mapping with high resolution,3D/4D structure information retrieval,and ultra-high resolution observation.In application aspects,it is featured by efforts to realize the high precision,large scale and time continuous monitoring and evaluation of the Earth surface dynamic process,under the background of major global issues such as global change and global sustainable development.In this paper,we introduce the research background and significance of the new SAR technology for earth observation,and then analyze the progresses of four typical advanced SAR technologies for the past decade,including polarimetric SAR (PolSAR),polarimetric interferometric SAR (PolInSAR),tomographic SAR (TomoSAR),and ultra-high resolution SAR (UHR SAR).Finally,the future development trend of the SAR earth observation technology is analyzed,mainly focused on four aspects:multi-channel information acquisition,multi-angle observation,high temporal observation,high resolution and wide swath mapping.