Abstract: This research combines theory with experiment to study the influence of thermal environment on the vibration characteristics of fiber-reinforced resin composite thin plate. Firstly, with consideration of the influence of base excitation load, the analytical model of fiber-reinforced resin composite thin plate was established in thermal environment and the analytical formulas of calculating the natural frequencies, modal shapes, vibration responses and damping ratios were derived, so that the corresponding solving procedure of vibration characteristic of such composite plate can be summarized. Next, TC500 fiber/epoxy composite plate was taken as a study object and its vibration characteristic was measured based on the established vibration test system in thermal environment. It has been found from the experimental results that when the temperature increases from 20℃ to 200℃, the modal shapes of composite thin plate can hardly be changed, while the natural frequencies will decrease between the range of 2.3%-36.6%, the vibration responses will increase between the range of 15.3%-58.4% and damping property also shows the upward tendency, e.g. when the temperature reaches to 200℃, the first 6 damping ratios will rise from 13.9% to 56.4% compared with the ones at room temperature. Besides, by comparing the theoretically calculated frequencies, shapes, vibration responses and damping parameters with the corresponding experimental results in different thermal environments, there is a good agreement between them. Therefore, the correctness of the analysis method and its results have been verified.