Abstract: To deal with the properties of early age concrete while allowing for the influence of curing temperature on the strength development rate and on ultimate mechanical behavior of concrete, the concept of “aging degree” is introduced. Using a mass concrete soleplate as an example, the thermal stress calculations in early age concrete with aging degree method are discussed using Finite Element method. To implement the aging degree method in finite element analysis, each element of the model must have different material properties that change at every load step, which is fulfilled in the analysis and the reason for no cracks in the mass concrete soleplate is explained.