Abstract: The distribution characteristics of weak intercalations and the development characteristics of landslides sliding zone in rock mass of the third Member of Badong Formation in new county-site town of Badong are studied in this paper. The results show that the sliding zone of landslides which developed in the third Member of Badong Formation corresponded to the sedimentary interlayers in the original rock. The intercalated dislocation caused by tectonic process in the interlayers evolved to landslides sliding zone by groundwater sliming effect. This effect is shown as the gravels with intercalated mud or the clay with intercalated gravels. The analysis shows that the deep-seated deformation in Huangtupo landslide and Zhaoshuling landslide were related to the broken rocks caused by the secondary fold and interbeded cleavage. The difference between the two landslide structure lied in the interlayer density in the original rock mass.