We investigate the (002) lattice strain evolution of triaminotrinitrobenzene (TATB) grains inside one TATB-based plastic bonded explosive (PBX) through the in-situ neutron diffraction.By comparing the untreated specimen with the thermal-treated one,it is found that the volume-average response of measured TATB grains remains nearly elastic during quasi-static uniaxial compression.The observed changes in TATB (002) lattice strains correlate tightly with the evolution of damage.A damage parameter defined by the macroscopically determined residual strain is further used to describe the damage degree of PBX,which suggests that the compressive behavior of TATB-based PBX is significantly influenced by the damage evolution.