Abstract: The use of fiber reinforced plastic (FRP) plates and sheets for strengthening masonry structures have already been implemented actually. And the performance of the interface between FRP and masonry is one of the key factors affecting the behavior of the strengthened structure. This paper presents an analytical solution model based on the experimental piecewise local bond-slip law, and the analytical solution model is capable of predicting the entire debonding propagation process. Expressions for the interfacial shear stress distribution, slip and normal stress distribution of FRP section are derived for different loading stages. The effective bond length is defined and the analytical solution is acquired. The debonding process is discussed in detail and the analytical results are compared with experimental data well.