The definition ofJ-integral of interfacial crack was introduced.The three.point bending tests were carried out to obtain the criticaI lOading values when the interfacial crack initiation occurred between coatings and substrates.The finite element analysis(FEA)was adopted to analyze the stress distribution in the specimens and compute the J-integral of the interfaciaI crack between LX88A coating and Chinese 0345 steel.The results showed that the average value of critical J-integral iS 0.70 N/m.which can be taken as the fracture parameter to evaluate the interfaciaI fracture behavior for the three-point bending specimens of LX88A coating/Q345 steel system.