Abstract: Intermediate crack debonding is a common failure mode of reinforced concrete (RC) beams flexually strengthened with externally bonded fibre reinforced polymer (FRP). This study analyzes the effect of the distribution of flexural cracks and the interfacial soft behavior on the interfacial shear stress of RC beams strengthened with FRP laminates under three-point loading. Based on the bilinear bond-slip model of the interface between FRP and concrete, an analytical solution of the interfacial shear stress in the intermediate crack zone is presented. A finite element (FE) model is established to validate the theoretical method and the effect of the crack spaces on the debonding load capacity. Comparisons among the results obtained from theoretical solution, experiments and FE method show a good agreement between the theoretical and FE results, and debonding load capacity obtained by theoretical analysis is smaller than those obtained by FE analysis and experiments. Moreover, the results show that the increase of crack space will decrease the debonding load capacity and the relationship curve between them can be simplified by a double broken line.