Response surface based finite element model (FEM) updating is studied. A finite element updating toolbox was developed using MATLAB as the development platform. The design of function and the interface were described. ANSYS was in tegrated with updating modules implemented on MATLAB using the parametric design language. The updating method and the toolbox were employed to update the FEM o f a steel frame using experimental modal data. The result shows that the method is workable and the toolbox is convenient and feasible.