Precision　grinding　on　brittle　materials　accomplished　without　generating　subsurface　fracture　damage　is　called　ductile-regime　grinding.　The　most　important　key　point　for　maintaining　a　ductile　material　removal　regime　is　to　ensure　that　the　cut　depth　made　by　grinding　process　does　not　exceed　the　critical　cut　depth.　Through　collecting　and　processing　the　acoustic　emission(AE)　signals　generated　by　zirconia　(PSZ)　ceramic　grinding　tests,　and　analyzed　the　characteristics　of　AE　signals　under　different　grinding　parameters.　As　a　result　of　the　experiments　described　in　this　paper,　it　can　be　concluded　that　AE　signals　measured　during　micro-grinding　are　sensitive　to　the　changes　of　cut　d-epths.　The　relationship　between　AE　signals　and　material　removal　regime　could　lead　to　an　in-process　sensing　strategy　of　the　cut　depths　for　ensuring　grinding　processes　under　ductile　regime.