Abstract: A new semi-analytical method is developed for the analysis of steady-state response of super-tall-mega space frame structures due to arbitrary deterministic dynamic loadings by using a three-dimensional model which is a combination of stiffened-thin-wall tubes on semi-infinite elastic body. The superstructure and its foundation are simplified equivalently and continuously into a combination of stiffened-thin-wall tubes and the subgrade is idealized a semi-infinite elastic body. A semi discretization is then made with some nodal lines, and the unknown shape functions defined on the lines are used as generalized coordinates, while interpolation functions are implemented between the lines. Using Hamilton’s principle, dynamic analysis of a super tall building structure is converted into the solution of the boundary problem of a group of ordinary differential equations, which can be solved by the precise and powerful ordinary differential equation solver. It is observed from the computing example that the new method is reasonable and feasible.