The relationship between the molecular structure of polymeric binders and mechanical properties of a TATB-based polymer bonded explosive (PBX) were studied by using five different fluoropolymers as binders to compare the quati-stastic and dynamic mechanical property, as well as the three-point bending creep property of the PBX. F- binder A, which was composed of vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE), endowed the PBX-A with the best mechanical strength and creep resistance ability. The fracture surfaces of the PBXs after the Brazilian tests were investigated by a field emission-scanning electron microscope (FE-SEM). The rupture mode in PBX-A and PBX-B was transcrystalline fracture together with interfacial debonding, but only interfacial debonding in PBX-C and PBX-D. It was explained that the C-Cl bond in CTFE played the key role to keep the polymeric binder rigid and increase the strength of the PBX.