The development and utilization of such complicated variable radial sand ridge tidal flat lies on the comprehension of its current situation, variation characteristics and laws. This paper approaches of remote sensing and Geographical Information System not only make the anatomizing to the radial sand ridges evolution laws more scientific and reasonable, but also extend the use of remote sensing technology in ocean. In this paper, we separately take a quantitative measurement and analysis on underwater topography, sand ridge and tidal creek. According to the sand ridges and tidal creek which build up the main geomorphologic type of the radial sand ridges, we found out their swing positions and range by the spectral measurement on the water content of tidal flat and the extraction of tidal creek medial axis respectively. Based on all these results, we come to the conclusion that some of the main sand ridges and tidal creeks have changed in recent two decades.For example, DongSha has been moving eastward, the deep trough on the west coast of the XiYang has been slightly silted, the east coast of XiYang has been moving westward.