Abstract: dentification of structural modal parameters using driven-base excitation is a modal analysis method of practical significance in development of space vehicles.A systematic exploration is presented in this paper.The theoretic Frequency Response Function under driven-base excitation, which is similar to those of tradinon methods, is derived.So the existing modal analysis system can be used to identify modal parameters under driven-base after a little algebraic modification of measured data.It is indicated that the method of driven-base has the same reliability as other traditional methods through computer simulation, cantilever tests and practical application.