Abstract: By complex potentials, a crack embedded in an infinite piezoelectric material under a far-field antiplane mechanical load and a far-field inplane electrical load is analyzed using permeable boundary condition. A closed-form solution of stress and electric fields is obtained. It is shown that the electric field is nonsingular in front of the crack tip, while the strain intensity factor, stress and electric displacement are of 1/2 order singularity. The energy release rate is always positive.