To understand the thermal fracture behavior deeply,the crack-tip characteristics for a functionally graded material ( FGM) plate with arbitrary thermomechanical properties under thermal load were studied. The temperature and thermal stress fields were derived by analytical method,and the loading on the crack faces was determined from the thermal stress distributions by using the superposition method. A finite element method based on nonhomogeneous elements was used to calculate the crack-tip fields of the FGM plate. Considering different distribution forms of the thermomechanical properties,the thermal stress intensity factors ( TSIFs) of the crack-tip were analyzed. It is found that the distribution forms can affect the crack-tip TSIFs greatly, which indicates that the actual situations may not be considered adequately if the material properties of practical FGMs are assumed to be one certain type of functions.