Abstract: Diamond abrasives were coated by electroless plating. Fixed abrasive pads(FAP) were prepared by using diamonds with different Ni covering ratio. The morphology of coated diamond abrasives were observed by scanning electron microscopy. The effect of Ni covering ratio on coefficient of friction(COF) and acoustic emission(AE) during the lapping process were investigated. Material removal rate(MMR) and surface roughness of K9 glass lapped by FAP with abrasives with different Ni covering ratio were compared. The results demonstrate that morphology of abrasives changes significantly with Ni covering ratio. COF, MMR and surface roughness increase first then decrease with the increase of covering ratio. Friction force between pad and work-piece, and cutting depth of abrasive grain into the work-piece are the highest when Ni covering ratio is 50% and the FAP exhibits a characteristic of self-conditioning. The MRR and its stability are the best when FAP embedded with diamond abrasives with a Ni covering ratio of 50%.