Interface dislocations may dramatically change the electric properties,such as polarization,of the piezoelectric crystals.In this paper,we study the linear interactions of two interface dislocation loops with arbitrary shape in generally anisotropic piezoelectric bi-crystals.A simple formula for calculating the interaction energy of the interface dislocation loops is derived and given by a double line integral along two closed dislocation curves.Particularly,interactions between two straight segments of the interface dislocations are solved analytically,which can be applied to approximate any curved loop so that an analytical solution can be also achieved.Numerical results show the influence of the bi-crystal interface as well as the material orientation on the interaction of interface dislocation loops. Interface dislocations may dramatically change the electric properties, such as polarization, of the piezoelectric crystals. In this paper, we study the linear interactions of two interface dislocation loops with arbitrary shapes in generally anisotropic piezoelectric bi-crystals. A simple formula for calculating the interaction energy of the interface dislocation loops is derived and given by a double line integral along two closed dislocation curves. Particularly, interactions between two straight segments of the interface dislocations are solved analytically, which can be applied to approximate any curved loop so that an analytical solution can be also achieved. Numerical results show the influence of the bi-crystal interface as well as the material orientation on the interaction of interface dislocation loops.