The seismic response of rock slope is one of the most significant issues in the field of geotechnical engineering. In this study, the intake slope of Zipingpu project is investigated to study the influence of Wenchuan earthquake based on the monitoring data. From the perspectives of time and space, the characteristics of supporting load and slope displacement have been analyzed before and after Wenchuan earthquake. Furthermore, the synergistic effect of slope shape, rock mass structure and supporting load under seismic force is discussed. The results show that the sudden increases both in deformation and supporting load of slope are principally caused by the seismic force, and thus earthquake is regarded as the main influencing factor. It is found that the change of supporting load caused by the earthquake is below 100 kN, which is less than 5% of the design load. Permanent displacement of the slope in horizontal direction is within the range of 12 mm and the deformation distribution in depth is controlled by the structural plane of rock mass. Particularly, the maximum displacement concentrates in the middle part of the slope. Free surface amplification effect has been found along the horizontal direction, while there is no obvious vertical amplification effect along the elevation direction. Therefore, this research can not only underpin the understanding of the dynamic response mechanism of anchored rock mass, but also provide references for the aseismic design of slope engineering controlled by the displacement .