During the assembling and installation of a surface casing into a subsea well, the casing string is hanged by its top end and free to move at the bottom end. The floating platform motions generates dynamic loads on the whole string. In this article, we assess the dynamic stresses along the surface casing using a commercial software for riser analysis. Three 20" surface casing strings with different lengths (400 m, 731 m, and 1036 m) were used as model for numerical simulation. The results show that, at the top and middle parts of string, the main component of the Von Mises stress is the axial tension; and the lower part of casing has the bending stress as the main component. Further, the effective tension results show that, for the shortest casing, axial compression may occur. Despite, such dynamic stresses are relative low compared yield stress of the material, the prolonged action of such dynamics loads may result in fail of connectors or other components.