Abstract: A generalized method of cell(GMC) with weak interface was developed to model the interface debonding within continuum fiber reinforced composite.To accomplish this work, the average displacement continuum condition between sub-cells in original GMC was modified by employing weak interface theory.Then the average strain of subcell was expressed in terms of global strain.By using the local constitutive equation, the relationship between average stress of subcell and the global strain was established.At last, the evolving compliant interface model was employed by GMC to model the global response of fiber reinforced composite under transverse loading.The result shows that the methodology developed here is appropriate to model the interface debonding.