Abstract: The interaction effects between a circular inhomogeneity with imperfect interface with cracks and a screw dislocation located at any point inside the matrix is investigated. By means of Riemann-Schwarz’s symmetry principle integrated with the analysis of singularity of complex functions, the general solution of this problem is presented. As a typical example, the closed form solutions for complex potentials in the matrix and the inhomogeneity regions are derived explicitly when the imperfect circular interface has a single crack. The image force acting on the screw dislocation is then calculated. The influence of the imperfect interface with cracks and material mismatch on the image force is discussed. It is shown that, comparing with the perfect interface with cracks, the imperfect one has a more effect upon the image force. The trapping power of the imperfect interface with cracks to the dislocation may be higher than that of a perfectly bonded one. When the inhomogeneity is hard, an unstable equilibrium position is found where the image force on the dislocation caused by the imperfect interface, the cracks and the inhomogeneity is zero, With the soft inhomogeneity, the dislocation is always attracted by the imperfect interface, the cracks and the inhomogeneity.