Grain boundary (GB) structure significantly contributes to the properties of polycrystalline materials. The objective of this work is to quantify the role of GB structure and energy on fracture behavior under tensile loading. Molecular dynamic (MD) calculations were performed for five aluminum (At) bicrystals with 〈100〉 symmetric tilt axes. The cohesive zone model (CZM) was used to analyze the fracture process. The simulation results indicate that the presence of certain GB structural units result in lower yield strengths and asymmetric crack growth behavior. The atomic traction-separation results suggest a strong correlation between cohesive energy of the interface and the GB energy. Finally, a framework is presented to characterize interfacial fracture of GBs through continuum interface separation constitutive laws that are informed from MD simulations.