The mechanical wear of abrasive diamond grit was investigated during scratching on Ta12W with acoustic emission (AE).The AE timedomain signals of wear progression for diamond grit were captured to analyze the characteristics of power spectrum.Meanwhile,the time series AR models of the wear progression were built.Experimental results show that the wear of single diamond grit is stage variation with the increasing of workpiece removal volume.With the increasing of diamond grit wear,the amplitude of timedomain signals is increased and the main peak frequency is transformed from high frequency to low frequency.Besides,the peak frequency of power spectrum is also increased.The diamond grit wear and the characteristics parameters of AE are appeared to be linear effect relationship;however,there is a negative linear relationship with the parameters of AR model.There is a well mapping relationship between the diamond grit wear and the AR model of AE signals.