Abstract: The tensile behavior at different temperatures of a single crystal Ni-base superalloy was studied.It was found that temperature and the crystal orientation has notable effect on the elastic properties of the alloy,and the elastic modulus of the alloy can be defined with a single variable,which is the three-dimensional crystal orientation parameter of the specimen.Moreover,the yield strength and the tensile strength of the alloy depend deeply on temperature and the crystal orientation index,the yield strength of orientation is higher than that of at room temperature,and shows the lowest yield strength at high temperature.