The status quo of THz spectroscopy and imaging of explosives are discussed. The THz radiation are very sensitive to the explosive of different temperatures and crystal structures in explosive structure inspection. The THz absorption spectrum of chemical mixture can be analyzed by linear regression to identify the composition and its relative content in the mixture according to the absorption spectrum of pure compounds. Terahertz time-domain spectroscopy can be employed to study the sorption of water content, which can identify the distribution of water in the surface of explosives.