Abstract: An endochronic damage constitutive model is proposed. The characteristics of the model are that the elasto-plastic properties and internal defects of concrete are described by endochronic theory and damage mechanics respectively, so that the concept of yield surface is not needed. The number of parameters is reduced significantly in the model which makes the model more applicable to engineering practice. The proposed model is used to analyze deformation and strength of roller compacted concrete specimens. The calculating results are in good agreement with experimental data, which can be used as guidance for RCC gravity and arch dam construction.