In the casting process, It is possible to minimize shrinkage and blowhole by working on modifying casting system, but to remove them completely is impossible. So the parts are exposed to working load. It is traditional to assume completely soundness in initial state of casting part which is excluding shrinkage and blowhole in manufacturing process. So design engineers apply sufficient safety factor because of possibility of unexpected performances of cast products. It would lead to a lot of error during fatigue life analysis. In this paper, we studied on prediction method of fatigue life of cast product containing shrinkage by using CT and SSM and conduct static and fatigue analysis. After analysis, experiments were conducted with specimens that have widespread porosities and predicted fatigue life used by strain-life and lefm method. Subsequently fatigue life from computational simulation and predicted life by theory compared with experiments results. Through this study, we can predict fatigue life of casting product by SSM(shape simplication method)