China is one of the largest oceanic countries in the world. China Seas, particularly southern CHina sea areas, is often dominated by rainy, foggy and cloudy weather that it is difficult to detect the near-real time, continuous marine environmental conditions, such as wind fields, surface waves, surface current and tidies, meso-scale eddies, fronts and coastal dynamic changes etc. SAR becomes a powerful tool for observing oceanic phenomena. In the paper, SAR, imaging, remote sensing methods and information extraction of oceanographic features are presented and analyzed in detail. The end of the paper, the potential of SAR images in marine applications is summarized.