<p>This study considered the transient behavior of two bonded dissimilar functionally graded piezoelectric (FGP) rectangular planes clamped along two parallel sides with multiple interfacial cracks. The material properties were assumed to vary exponentially with the vertical coordinate relative to the interface of two bonded FGP planes. First, the integral transform method was used to obtain the dislocation solutions in dissimilar FGP rectangle planes with time-dependent Burgers vectors. Then, the problem is formulated in terms of singular integral equations with Cauchy kernels with the dislocation density as the unknown functions. The results consist of the problem of a single crack and the interaction of two and three interfacial cracks. It is shown that the dynamic stress intensity factors (DSIFs) are highly affected by the non-homogeneous parameter. Furthermore, the numerical results indicate that the crack length and the geometry of FGP planes and loading parameters may have a considerable effect on DSIFs.</p>