The bond between fibre reinforced polymer (FRP) plate and concrete surface has shown significant effect on the behaviour of strengthened reinforced concrete (RC) beam. Therefore, an intermediate crack (IC) debonding resistance which depends on the interface between FRP plate and the concrete surface remains as the main concern in designing RC beam strengthened with FRP plate. This research is to develop the bond slip model between the interface of FRP plate and concrete surface and to validate the model by carrying out experimental pull out test. Comparison was made between the new bond slip model and the existing bond slip model. It was found that the new bond slip model achieved very close results as compared to the published bond slip model.