///The wide angle seismic profile OBS973-2 that extends 369 km in NW-SE direction from the northeastern Liyue Bank to the central sub-basin is established by trial-and-error 2D ray-tracing method. This profile is compared with that in the northern continental margin for discussing the conjugation relationship between the northern margin and the southern margin. The result indicates that its continental crust is a standard one but its oceanic upper crust has relatively higher velocity than standard one. The seaward rising depth of Moho is 23 km in Liyue Bank and 8~12 km in the sea basin. The velocity beneath Moho is 8.0 km/s in sea basin, obviously smaller than 8.2 km/s in Liyue Bank. The comparison of profile OBS973-2 with a previous profile OBS2006-1 in the northern margin shows the remarkable similarity between them. This result and detailed discussion suggests a possibility of conjugation relationship between Liyue Bank and Zhongsha Massif.