The crack in concrete dam body is considered as a typical damage to concrete gravity dams during large earthquakes, and lots of researches on a nonlinear dynamic analysis method considering the occurrence and progress of cracks have been carried out in order to evaluate this behavior. But there are some problems to evaluate the safety of dam using nonlinear analysis: that the influence which the set material properties have on the results of nonlinear analysis is large, and that the results of nonlinear analysis differ greatly according to the damage estimation models or analysis programs. We, therefore, researched on evaluation indices which correlate well to crack progress in a concrete gravity dam based on the results of linear analysis, by comparing the results of crack progress analysis (nonlinear dynamic analysis) using smeared crack model in order to explore the possibility of estimating damages by the linear analysis method. This paper reports the evaluation indices based on linear dynamic analysis method and the characteristics of the progress of cracks in concrete gravity dams with different shapes using nonlinear dynamic analysis method.