Abstract：Experiments on acoustic emission(AE) characteristics of complete granite failure process are carried out under uniaxial multilevel loadings. Relations between stress and strain，and relations of time with AE characteristics and stresses are obtained. The results show that during load stability period，AE rate and AE energy decrease，but AE events remain constant approximately，which show that cracks are not developed and AE level is low. During load increase period，AE rate raises，indicating that cracks are developed. The uniaxial multilevel loading experiments reflect AE trend during stress regulation to certain degree when underground powerhouse is excavated step by step. It is suggested that，for rockburst geologic hazards，appropriate monitoring opportunity should be adopted during AE monitoring，especially AE monitoring should be strengthened when the upper and nether steps are joined. AE progress of rock failure includes initial phase，tempestuous phase and drop phase. When the curve reaches to its peak phase，major AE of events rock samples are active. Then AE events remain constant approximately and AE rate drop，indicating that there is a relatively quiet period. Compared with experimental studies of other scholars both in laboratory and in field，it is considered that relatively quiet period of AE appears before rock failure，and then，the phenomenon is discussed with physical mechanism. The relatively quiet period of AE before rock failure can provide reference to rock mass stability monitoring and prediction.
