Abstract: The characteristics laws of acoustic emission for the whole coal failure process under splitting test and uniaxial compression were studied comparatively. The results show that, in the process of uniaxial compression, acoustic emission signals are relatively few at the beginning of the stress, which increases dramatically during the late elastic and plastic deformation stages. The signals are the strongest during the failure stage. In the process of splitting test, acoustic emission signals are detected during the crack accelerated non-linear elastic deformation stage, the energy and pulse numbers are in the peak during the failure stage. However, the acoustic emission signal has a time lag. Compared with the uniaxial compression, acoustic emission signals produce later in the process of splitting test, the energy of acoustic emission is relatively lower while the pulse numbers of acoustic emission increase relatively. In addition, the pulse number is larger during fracture compaction stage in the uniaxial compression whereas the similar phenomenon has not been observed in the splitting test.