Abstract:     The basic theory of the frequency response function (FRF) based updating method was presented, and then the influences of the measured noise, the selection of frequency point and frequency band on the updating result were studied by using a simulated truss structure model. The conclusions show that：First, frequency selection is a key to the success of the updating, and appropriate selection of frequency point can decrease computational costs, improve the condition of the sensitivity matrix and resist the effect of measured noise; secondly, improving the accuracy of the measured data and increasing frequency band used in the updating are effective ways to get better updated model.

Key words: Frequency response function, Model updating, Frequency point selection, Measured noise, Revision frequency band