Abstract: For RC structures strengthened with FRP, debonding failure may occur before the FRP rupture strength is reached, and the strengthening effect is accordingly declined.It's believed that the research of RC structures strengthened with FRP is found on the analysis of bond behavior of the interface between FRP and concrete.Based on the experimental research of Tan Zhuang, the finite element method is used to analyze the bond behavior in the interface by using MSC.Marc program.The concept of "crack band model", "interface bonding capacity" and the "effective anchorage length" are introduced, the optimization of concrete element softening modulus and the shear model over crack is carried out.The FRP strain and the anchorage bonding stresses along the extensional bond length are obtained, and the distribution law is investigated, a brand new concept of "bonding yield deck" is proposed, the method is recommanded for relative nonlinear FEM analysis of bonding behavior.