Why deep earthquakes are in subducted oceanic slab? By studying the non-double-couple seismic radiations of deep earthquakes, Li et al. (2018 nature geoscience) found that deep earthquakes are, like shallow earthquakes shear dislocations, but in anisotropic laminated fabric. In this talk, I’ll review these findings and propose possible origin of the anisotropy. Predictive testable hypotheses will be put forward for people to test the anisotropy idea.