In this paper, the crack-tip field intensity factors of a piezoelectric crack are respectively evaluated by an interaction integral (M-integral) and a modified crack closure integral method (MCCI). By applying the dual BEM to piezoelectric crack models, the crack-tip fracture parameters using M-integral and MCCI are verified by the existing analytical solutions and compared with the results by the classical displacement extrapolation and J-integral methods. Some examples are presented to show the high accuracy of M-integral and the improvement of MCCI for the piezoelectric crack problems.