Abstract: According to new data on the sea gravity,marine and aviation magnetic and seismogram sections,and together with old data, the authors have worked out maps of the free-air gravity anomaly,Bouguer gravity anomaly and magnetic anomaly. Based on the maps, the north edge fracture of the North Yellow Sea basin has been systematically analyzed by combining traditional processing method with multi-scale decomposition of wavelets. The basic characters of the north edge fracture of the North Yellow Sea basin have been confirmed, and the extension length, the depth and the characters have been analyzed. The authors point out that the fracture is the borderline of the Liaodong apophysis and the North Yellow Sea basin, both sides of it have different geophysical fields and the fracture has the characters of multi-period activities and controls the formation and evolution of the North Yellow Sea basin.