Abstract: Due to passivation and wear, fixed abrasive lapping pad needs to be conditioned.Material removal rate is one of the characteristic indexes to judge the condition of the lapping pad.The relationship between acoustic emission signal and material removal rate is beneficial to optimize conditioning of lapping pad, improve the processing efficiency and reduce the production cost.The effect of lapping pressure, lapping speed, abrasive size and slurry pH on the removal rate and acoustic emission signal is investigated in fixed abrasive lapping K9 glass.The linear regression equation of material removal rate and root mean square of acoustic emission signal is established.The results show that the influences of the four factors on material removal rate and acoustic emission signal is the same, and the prediction error of the regression equation is less than 5%.Acoustic emission technology can be used to predict material removal rate in lapping process, which lays the foundation for on-line monitoring fixed abrasive pad condition.