In this study

acoustic emission (AE) tests were conducted on altered granite gneiss specimens under uniaxial compression conditions. The evolution laws of AE events during the failure processes of specimens were further investigated. The results showed that for most specimens

the first occurrence of the high-energy level AE event indicated that the specimens were at the high-stress level. It is found that the stress level further increased when the intermediate-energy level AE events distribute throughly in specimens. The imminent rock failure was identified by the occurrence of the high-energy level AE event in the final through-going area. For brittle failure specimens

the through-going distribution phenomena of the intermediate-energy level AE events would not occur. For specimens contained weak-zones

the first high-energy level AE event took place at the low-stress level. In the meantime

the intermediate-energy level AE events gathered in a band shape around the high-energy level AE event. However

the density and energy level of AE events were low in the area far away from the high-energy level AE event. The research results can provide a testing basis for the identification of stress level and the evaluation of rock stability.