Abstract: The numerical methods of sensitivity analysis and designoptimization for structures with transient thermal deformation and thermalstresses as design criterions are studied in this paper. In the sensitivityanalysis of thermal stress and deformation, two kinds of algorithms of thedirect method and the adjoint method have been proposed and the couplingeffect of temperature field is considered. To deal with the coupling effectof temperature field, the derivatives of temperature field with respect tovariables are required in sensitivity calculation for thermal loads andthermal stresses in the direct method, while the derivatives of thermal loadwith respect to the temperature field are required in the adjoint method. Anumerical example is given to demonstrate the effectiveness of shape designoptimization reducing the thermal stress, evaluate the accuracy ofsensitivity analysis methods, and show the effect of temperature fieldderivatives in the coupling sensitivity analysis. The implementation of theadjoint method in application software provides efficient sensitivityanalysis for large-scale problems of structural design optimization.