Abstract: In order to study the anisotropy of coal pores and fractures, further reveal the microstructure and physical characteristics of coals, coal samples were collected from Pingdingshan eighth mining area for nuclear magnetic resonance(NMR)experiments, transverse relaxation time(T₂) and magnetic mesonance imaging(MRI) under uniaxial loading were compared and analyzed. The results showed that T₂ was remarkably anisotropic:parallel to bedding and in direction X of vertical main fractures, T₂ had three peaks, parallel to bedding and direction Y of main fractures, T₂ had two peaks, vertical to direction Z of bedding T₂ had one peak. After uniaxial loading, the spectral area of T₂ and the porosity decreased, the percentage of peak area induced by porosity variation in direction X and Y declined, but the fracture areas ascended, the fracture area in direction Z declined. The MRI revealed that under uniaxial loading, most pores and fractures parallel to bedding were closed, some fractures had radial deformation, most fractures of loading direction were closed, the compaction effects was remarkable. In summary, under uniaxial loading, the anisotropic characteristics of coal samples were remarkable, and the NMR was an effective method to study microscopic changes of coal pores and fractures.