Abstarct: Water is one of the most important vital material that the human try to save it with different procedures from the first day of creation, and wherever that the water was sufficient there were start point of the new culture. Dam is the one of the facilities that human built it to save this vital material and in the fallowing of the building dam human able to use water in other ways like energy generation. Firstly, dam building started with building the small dams, and then with progress technology the bigger dams built. Destroying the huge dams furthermore financial damages, if a village and residential area exist in the lower part it can have irreparable damage to human life. For this result engineers and researches are always searching for more certain analysis for these huge factors. Earthquake is one of the reasons of breaking and destroying of these dams that the pressure of the Reservoir's water in result of earthquake to dam's body must be exactly determine. For the aim of exact calculating of existing water pressure to the body of the dam it needs to calculate the effects of hydrodynamic pressure in while of earthquake and in addition the pressure hydrostatic must calculate exactly. Dynamic analysis for earthquake of the concrete arc dams are more complicated than buildings. This complication is the result of inner competence of Reservoir's water and factors. In result of earthquake, pressure alternation and hydrodynamic effects resulting from earthquake on the dam and foundation, is necessary and important factor that must be consider in dynamic analysis. In the past, many ways were exist for determine hydrodynamic pressure that divided in two main ways, analytical and experimental, that they were accompanied with simplifying hypothesis and the reason of this was they hadn't an exact recognition from this phenomenon and they consider this ineffective. Today with technology progress, old ways replaced with modern ways. In modern ways it is necessary that limitation and simplifying hypothesis as could as possible don't delete and consider in calculations to gain exact and more realistic. in this research with using the ANSYS15 dynamic analyzing software on Sari-Shahid-Rejaei dams and the result that gain in field of hydrodynamic pressure with experimental procedure and at last the results show that the general trend over older methods have relatively good conformity with the numerical methods and with considering the result in the field of consistency and resistance of the dam modeling and numeral analyzing of the dam can be effective with stress and strain contours and it can be resulted that Shahid-Rejaei dam with the occurrence of the earthquake damage is not too much and the body and the foundation can tolerate the pressure from the earthquake.