Abstract: In civil engineering, concrete structures often suffer dynamic loadings. Earthquake is an important load for dynamic analysis of concrete structures especially for high arch dams. Thus, it is very important to analyze the dynamic properties of concrete and present reasonable and practical models for dynamic analysis of concrete structures. Most concrete dynamic models in the literature are macroscopic and empirical, which cannot describe the micro-mechanism of concrete material precisely. A micromechanical model is presented in this paper. A comparison between the theoretical result and the experimental data in the literature indicates that good agreement is achieved, which implies that the model can be used to explain the rate-dependent properties of concrete.