The　piezoelectric　strain　constant　d33　of　PZT-4　ceramics　with　electrode　can　drop　from　380　pC/N　to　0　by　CO2　laser　irradiation　under　suitable　laser　power　density　when　the　irradiation　time　is　2　s,　5　s　and　10　s　at　normal　temperature　and　pressure.　The　relationships　between　d33　of　PZT-4　ceramics　and　laser　power　density　and　laser　irradiation　time　are　investigated　systematically.　Based　upon　the　characterization　of　XRD,　Raman　spectra　and　traditional　annealing　treatment,　it　is　suggested　the　electric　domains　of　irradiated　PZT-4　ceramics　become　unordered　and　polarized　state　degenerated　by　thermal　effect　of　CO2　laser　irradiation,　which　causes　its　piezoelectric　properties　vanish　with　phase　unchanged.