In recent years, High-Rise buildings are increased. For this reason, using large size member of framework is inevitable. High hydration heat which is caused by large size member of framework makes structure to take serious risk of durability. To solve this problem, a variety of researches are proceeding. Recently, several studies about decreasing cement hydration heat by using Urea are reported. In this study, thermal performance evaluation experiment conducted on cementious materials using urea. In addition, hydration heat is predicted through theoretic consideration and conducted comparative analysis of difference between the results from experiment and theoretic prediction. Results of experiment showed hydration heat was decreased by increasing amount of urea addiction. Through a comparative analysis, error range is included in plus or minus five percent in the dissolution test and thermal performance evaluation test of cement mortar.