Abstract: Aiming at the problem that ceramic materials will generate a large number of acoustic emission signals in the process of loading damage, the fracture processes of 95% alumina ceramics and 15% zirconia toughened alumina (ZTA) ceramics under compression using acoustic emission (AE) method were compared. The spectra of their failure processes were obtained by decimation-in-time fast Fourier transform (DIT-FFT). The analyses of AE oscillograms, spectrograms, hits, and amplitude distributions of the two kinds of ceramics show that AE signals emit from ZTA have much higher amplitudes and lower frequencies during their failure.