Abstract: An efficient numerical method for the finite-element model updating of damped gyroscopic system was developed based on incomplete complex modal measured data.It was assumed that the analytical mass and stiffness matrices were correct and only the damping and gyroscopic matrices need to be updated.By solving a constrained optimization problem,the optimal corrected damping matrix and skew-symmetric gyroscopic matrix complied with the required eigenvalue equation were found under a weighted Frobenius norm sense.