A new method has been developed to predict the dynamic response of a large spacecraft in acoustic environment during launching. In this study, emphasis was placed on the importance of the effects of the equipment masses attached to spacecraft panels. These effects are not taken into account in traditional methods, such as Statistical Energy Analysis (SEA). It is shown that the dependence on frequencies of equipment responses differs from that for responses of bare sections of the same panels. Emphasis was also placed on the effects of change of radiation efficiency of a panel due to equipment attached to the panel. When the number of equipment attached to a panel is large, the effect of radiation effiency change on the panel response is extremely important. The new method has been applied to predict the dynamic response of a model panel of Engineering Test Satellite-VI (ETS-VI). Agreement between predicted results and measurements is excellent.