The lower member of Xingouzui Formation（Ex）of Paleogene in Jiangling sag is rich in gypsum-salt rocks. The hydrocarbon accumulation is closely related to the distribution of gypsum-salt rock. By analyzing the cores，logs and seismic data，it is found that the lithologic and the electric characteristics of gypsum-salt rocks are low density and high electronic resistivity. Based on forward modeling，their seismic responses are characterized by high amplitude and low frequency. Combined with well-seismic calibrating，it is found that different lithologic has different seismic response. The seismic reflection characteristics of gypsum-salt rock are strong amplitude，low frequency and good continuity. Seismic responses of the interbeded sand and shale are characterized by strong amplitude and bad continuity. Weak amplitude reflection feature appears in mudstone. By extracting the seismic attribute data，the characteristics of seismic attributes of typical facies were determined，and the relationship among lithological facies，seismic response and seismic attribute was established to predict the gypsum-salt distribution in the undrilled zone based on the drilled area in Jiangling sag. In conclusion，gypsumsalt rock in Lower Ex of Jiangling sag distributes in two areas of the southern of Meihuaiqiao subsag and Zifusi subsag.