<p>The reservoir landslide undergoes periodic saturation-drying cycles affected by reservoir fluctuation in hydropower project area, leading to the irreversible impact on the landslide materials. Sliding zone is the shearing part in formation of landslide and controls the further development of landslide. The mechanical behavior of sliding zone soil under compression is a crucial factor in the stability analysis in landslides. In this paper, the sliding zone soil from a giant landslide in the biggest hydropower project area, Three Gorges Reservoir Area, is taken as the research case. The particle-size distribution of the sliding zone soil from this landslide is studied and fractal dimension is adopted as representation. Periodic saturation-drying is introduced as the affecting factor on sliding zone soil properties. The triaxial compression test is conducted to reveal the mechanical behavior of the soil, including stress-strain behavior, elastic modulus, failure stress and strength parameters. These behavior of sliding zone soils with different fractal dimensions are studied under the effects of periodic saturation-drying cycles. The normalized stress-strain curves are displayed for further calculation. The data considering saturation-drying cycles are obtained and compared with the experimental results.</p>