Abstract: The Yellow Sea is a more active area of strong earthquake in the edge basin of East Asia Continent. Many great earthquakes occurred in the history,and caused a lot of damages to the sea bank and the engineerings at the bottom of the sea.In this paper,the analysis of the seismic pictures of the maritime space according to the network records in China demonstrates that the seismic level in the Yellow Sea is similar to that in the continent.Applying the clustering law,the seismic lines were drawn,and through comparing with the geotectonics,we can say that the maritime seismic lines basically reflect the profile of active faults on the bottom of the sea.The great seismic lines are in NE and NW direction,and may reach the Korean Fesile.In direction,the seismic lines in NE direction are in accordance with the Moho surface in the Yellow Sea,which shows that they have the background of deep tectonics.As to the structure in NW direction,that is also obvious.