The concrete gravity dams are huge structures storing a large amount of water. For this reason, they cause especially irreparable loss of lives during the earthquake. The stability of a structure is associated with safety level of the structure. The stability of a concrete gravity dam is in accordance with evaluation of safety factor against sliding with using equivalent static loadings acting friction model of dam-soil interaction zone and dynamic effects of earthquake on the dam. In this study, the sliding stability of concrete gravity dams is evaluated with Multiple Wedge Analysis method based on Mohr-Coulomb Failure Criterion. Sariyar concrete gravity dam is chosen as a numerical application. For usual and unusual loading conditions, the effects of the parameters which are dam base angle, cohesion and internal friction angle of soil, uplift pressure and earthquake loads on the sliding stability of the dam are investigated. The changing of safety factors obtained according to the analysis is evaluated and the parameters acted on sliding stability of the dam are determined. After the analysis, it is shown once again that acceleration of earthquake has the most important effect which can hazard the sliding stability for dams. Cohesion and internal frictional angle of the soil interacting with the structure are other two important parameters which determine sliding stability. It is shown once again that uplift pressure has a detractive effect on sliding stability. In addition, it is established that the changing of dam base angle affects sliding stability.