The displacement vector field can be represented in terms of a scalar potential ${phi}$ and a vector potential ${phi}$. The scalar potential ${phi}$ is related to dilatational waves and the vector potential ${phi}$ is related to rotational waves. Using these two complex displacement potentials, the stress and displacement fields for steadily growing interface cracks in dissimilar materials are obtained. The energy release rate for steadily growing interface cracks in dissimilar materials are also obtained. And with photoelastic isochromatic patterns simulated by computer graphics, the stress intensity factors are discussed.