The relationships between molecular and crystal structures of explosives and their sensitivities are reviewed. Which include the theory criterions from molecular structures, such as nitro group charge, interaction energy among substitutes, electron-attracting ability, bond dissociation energy, bond order, bond gap between Highest Occupied Molecular Orbital (HOMO) and Lower Unoccupied Molecular Orbital (LUMO), electrostatic potential at the midpoint of the C—NO₂ bond, and nuclear magnetic resonance (NMR) chemical shift; and the impact effect of the anisotropy of crystal, π-stacked structures, and hydrogen bond on sensitivities in crystal packing. And it will be necessary to explore the sensitivities on the mesoscale level in the future. 