A mesoscale model for the characterization of creep and shrinkage of cement based materials is evaluated and proposed. It is the first mesoscopic model for cement based materials time dependent behavior. The model is justified by statistical comparisons with RILEM data. The analytical part of model is developed using Solidification Theory, Kelvin type Theological models, and Drichlet Series. The form of constitutive equation is derived from the assumption that the aging is caused by volume growth of the load bearing fraction of mortar during hydration. Concrete is modelled as three phased composite system, as mortar, aggregate, and aggregate-mortar interface. The aggregate shape and grading is designed by the written program according to Turkish and American Standards. The whole concrete cross section is simulated by using lattice type modeling algorithm. Numerically generated concretes creep and shrinkage behaviors are evaluated and cross section of the specimen is reshaped. Thus, the behaviors of each three phases are observed according to aggregate type, shape, and grading, cement content and ingredients, water, temperature, cross section, and volume of whole concrete. The simulation results are confirmed some of the existing theories and provided new information on concrete creep and shrinkage.