Abstract: Cemented tailings backfill samples were produced with tailings from a a copper mine by different ratios. Experimental tests were performed on the cemented tailings backfill samples for the characteristics of acoustic emission (AE) under the condition of uniaxial compression. The testing results confirmed that the AE series is of fractal characteristics upon theoretical analysis on the basic parameters of AE. G -P algorithm worked out the correlation dimension of AE. The correlation dimension of low ratio (1 :8) samples reduced to the minimum when the stress level increases to 60 %. Most of the micro-cracks begin an orderly expansion and rapidly increases. The correlation dimension of the high ratio (1:4) samples gradually reduces to the minimum when the samples start to break down. The dump-quiet period model and long-term decline model can be used as the precursor criterion for monitoring and forecasting of the stability of backfill.