Microstructures of the localized shear bands generated during explosion with a thick-walled cylinder specimen inTi-6Al-4V alloy, were characterized by TEM and SEM. The results show that the twinning is a major mode ofdeformation, and the distortion-free grains in the bands with the size of 10μm in diameter were proposed to be there-crystallization during dynamic explosion. The further observations show that the α → α2 phase transformation may occur in the bands, and this kind of transformation could be confirmed by its dark field image and electron diffraction analysis. Analysis shows that there is specified orientation between the α and α2 Phases.