A faulted rock usually shows the swelling behavior because of clay minerals which consist of the fault gouges. It makes rock mass unstable and threatens the safety of structures built in rock mass. This study was aimed at clarifying characteristics of physical and mechanical properties of faulted rock materials. At first, microstructures and mineralogical composition associated with faulting in the fault gouge zones were analyzed by using X-ray diffractometry (XRD) and SEM microphotographs. Physical properties of the faulted rock materials from fields were measured in the laboratory. It is well known that the mechanical properties are sensitive to the mineralogical assemblage and are affected by the shapes, distribution and preferred crystallographic orientation of the components. Material and direct shear tests were also conducted on faulted rock materials under saturated and unsaturated conditions. The mechanical results were analyzed together with the analyzed result of XRD and SEM.