Abstract: To study the interfacial bond stress between a timber beam and CFRP sheets, the static tests of 6 timber beams strengthened with CFRP sheets are carried out. The distribution of strain on the end of CFRP sheets is obtained, and the average interfacial bond shear stress was calculated based on the strain of two adjacent points. Formulas for calculating interfacial bond shear stress and bond normal stress between the CFRP sheet and the timber beam are deduced by neglecting shearing deformation of CFRP sheet and timber beam, and coefficients under two symmetric point loads are presented based on boundary conditions. The interfacial bond shear stress of experimental beams is calculated using the method above, and the results are in good agreement with those of experiment, showing that the method is feasible.