Brazilian disk splitting tests were conducted on the granite disk specimens to study the feasibility of indexes based on AE parameters (i.e.

RA and AF) for illustrating the fracturing intensity of rock failure. The distributions of RA and AF during the loading process were studied and compared with the results of SiGMA moment tensor analysis. The results show that the number of the shear cracks increases with approaching the damage stage even in the tensile failure of rock. The suggested judgement value for analyzing the failure mechanism based on RA and AF was proposed. An index r=RA/AF was proposed to illustrate the fracturing intensity of rock failure and was further compared with the amplitude parameter of distribution

variation and attenuation characteristics. The results show that the evaluation based on the index r leads to more conservative results. Furthermore

the coefficient of variation of r was proposed to be the statistical index of r and compared with b value

which is the statistical index of the amplitude. The results verified the feasibility of CV(r) in evaluating rock failure and the judgement value of granite splitting failure was suggested according to the b value.