Abstract: This paper focuses on the study of the natural vibration characteristics and dynamic response of an orthotropic plate under thermal environment by means of experiment and numerical calculation. The variation of natural frequency as well as the interchange of the mode shape and response under excitation during thermal environment are the key points in this research. The result shows that the thermal stresses and thermal deformation due to thermal loading will change the dynamic characteristics of an orthotropic plate. The thermal stresses and thermal deformation are of different effects on the stiffness of the plate, will result in a trend that the fundamental frequency firstly lowers and then rises, and whose slight variation leads to a mode-shape interchange of the plate. The dynamic response curve shifts to the low frequency range with temperature rising.